Compound slide assembly on a LeBlond NK Series lathe. The plunger at the 5 o'clock position on the cross-slide end bracket (behind the micrometer dial) is a special LeBlond stop used when threading to make returning the cross slide both easier and more accurate.

Rear view of a LeNlond NK lathe in the Yancey Machine Tool Company. Mr. Yancey is walking by. The large "Gray" planer in the background was described as "the little guy"  - and not big enough for way grinding on the larger lathes.
The motor fastened to the lathe bed below the rear of the headstock is the original LeBlond fitting used to drive the hydraulic power unit motor for the "Servo Shift" system and the pumped lubrication to the headstock. The upright box to the rear of the headstock is the LeBlond factory-supplied electrical-control unit. Although at the time Yancey's had the "Servo Shift" working, no one was expecting it to be reliable.
Some personal observations by Joe Michaels, a user of LeBlond NK lathes and the Workshop manager of  American Power plant:
When the South Bend/Nordic 25 engine lathe in our power-plant machine shop "went south" (to be polite) we needed to look around for a suitable replacement. However, in our books, a Southbend/Nordic was never much of an engine lathe to begin with; it was built in France by Muller & Pessant and was simply too light in construction. The headstock internals were a joke and, to make matters worse, no spares were available. I chose not to replace this Nordic 25 with a new lathe. The only new large engine lathes available in the USA today come from China, or perhaps Eastern Europe, and, like the Muller & Pessant, do not have the sheer mass required for successful use with huge jobs and are known as "five-year throwaways. As a further disincentive to their purchase most of these imported machines now feature extensive use of "low-friction, high-molecular weight" polymers on their sliding surfaces. On heavy duty machine tools this is not, in my opinion, the best design - slides should run on good scraped-in surfaces - but, by using them, the builder's costs are reduced and they make for simpler manufacturing and fitting up.
The lathe (illustrated on this page) was located in the Portland, Oregon shop of Yancey Machine Tool Company. We were inspecting it for purchase and I subsequently went to contract to buy it for installation in our power-plant maintenance shop. Mr. Yancey is 78 years old and started out in rural Arkansas; he is pretty much self-taught and he and his sons undertake a range of specialized, one-off projects. Above all, the man is as good as his word for we have been on some real goose-chases and fool's errands looking at used machines.
Over the years Mr. Yancey has invented and developed a number of specialized machine tools as well as some very fine heavy-duty milling heads and that is how we discovered his firm; some years ago we bought a Cincinnati Hypro Planer from him that had been modified by the addition of two Yancey 30 HP milling heads that turned it into a very useful "plano-miller". The company continues to custom build heavy-duty milling heads as well as rebuilding and upgrading older US Machine Tools. A most remarkable machine he recently invented was used at the Three Gorges hydro-electricity project in China to machine the runners ("waterwheels") on site as they were just too massive to be built or machined at the maker's works. Mr. Yancey took the table from a giant gear hobber (I believe this had been used to hob ring gears used on battleship gun turrets in WW2), a section of bed from a lathe that had machined the 16" gun barrels for the USS Missouri, some parts from a GA Gray open-side planer and some castings he and his sons designed and made patterns for. These parts all fitted together perfectly to produce a "portable machine tool" complete with CNC controls and a closed circuit TV arrangement that could check the cutting tool when inside the crown of the big turbine runners, or boring the shaft fits. It was not only able to fully machine the waterwheels in one set-up but even static balanced them. The wheels, with an area of excess metal left on the periphery for balancing, were set on stands with strain gauges that transmitted the load at each bearing point to a computer; the computer then determined where the waterwheel was heavy and where light.  The program worked through the CNC drives to run the toolbit in and out as the machine's arm rotated about the center of the wheel. This then machined something that is eccentric, or "sort-of-round", getting a weight distribution to static balance the waterwheel. The "arm" on this specialized portable machine was the bed from the gun barrel lathe. I saw a video of tools represented by their sellers as being in good to excellent condition. When I called to ask Mr. Yancey if he had a used LeBlond lathe for us, he told me he had a "good one", of the right capacity that would be suitable; so, on his word we took a plane from NY State to Portland, Oregon - a long and expensive trip. If anything, Mr. Yancey had understated the condition of the lathe, it was in fine condition. Because the "Servo-Shift" mechanism was temperamental (and usually took a factory service technician to put right) the lathe was little used before being "mothballed" by the government. Because storage had caused some discoloration (and possibly corrosion) of the bed ways Mr. Yancey had been able to buy at the "right" price. Bigger LeBlond lathes all came with replaceable hardened bedways so, using a huge G.A. Gray planer in his shop (which he had re-scraped and fitted with a way-grinding head) Yancey Machine Tool fitted these parts and ground them in place, achieving  better-than-new accuracy. They also re-scraped the carriage wings, adding a slight relief at mid-span of about 0.0015". This modification lets the carriage "settle in" as it wears and eliminated the rocking found in many lathe carriages as they age. The cross slide also has replaceable hardened ways and came with a factory-fitted heavy ball screw ready for a taper attachment. Fortunately the headstocks of Servo-Shift lathes were left with the bosses inside that carried the conventional manually-operated shifter shafts. Because of this, and the fact that the gearing is like new,  the headstock is being converted back to a combination of manual shifting plus a drive by a modern programmable AC inverter unit so enabling us to get rid of the complicated electro-hydraulics. When finished the original 36 shift positions will be available plus infinitely-variable speed control via the inverter drive. It will also mean we can remove the electromagnetic clutch/brake and provide programmable acceleration deceleration and emergency braking through the inverter.
The carriage has power rapid traverse with its own "pancake" motor. The tailstock has a number 5 MT quill taper and--look at the size of that quill - it's big ! The big LeBlonds all used a two speed planetary drive on the tailstock quill with a cautionary note: "Running a center in with the quill drive in the lower speed range could well overload the center". There is also a "one shot" way lubrication pump on the tailstock base; you give it a shot of waylube to break the metal-to-metal contact and reduce the stick-slip friction before attempting to move it. Anything LeBlond did on these lathes was top shelf.
Massively built the headstock gearing uses a filtered, re-circulating lubrication system that provides a combination of pressure oiling to the bearings and a spray/trickle feed to the gearing. The compound slide micrometer dials are large, beautifully engraved with a satin chrome finish and fitted with neat friction-adjustment clutches. The taper-turning attachment (not shown) uses pre-loaded antifriction "cam follower bearings" as opposed to sliding surfaces. By way of comparison this 24" x 96" lathe was fitted by the factory with a 40 HP main-drive motor whilst the "Nordic 25" (also a 25" x 96" machine) had to make do with only a limp 7.5 HP main motor. In the upgrade we are going down to a 20 HP inverter drive (since we won't be hogging heavy forgings) and a 3/4 or 1 HP lubrication pump with automotive type filter because there will be no need to run the headstock hydraulic speed changer.
Both this lathe and the Nordic 25 use a D-9 spindle taper, so either the Nordic 25 was a flyweight, under-built machine or the LeBlond a genuinely over-engineered "bruiser" built without regard to cost. The top spindle speed on the LeBlond is 1100 rpm and it has a traditional "Norton" style quick change gearbox. LeBlond ran their quick change gearing "wet"- in their own oil sump while using a traditional "American-style" tumbler mechanism.
LeBlond's last years are well documented on the "LeBlond, Ltd" and "Makino" company websites. Mr. Yancey met the company's founder, R.K. LeBlond, many years ago and had been in touch with LeBlond over the years as he worked on many LeBlond heavy-duty lathes for specialized applications. Mr. Yancey said that had R..K. LeBlond been amongst the living, the "Servo-Shift" concept would never have seen the light of day, nor would the re-designed, light duty, late-model Regal lathes ever have come into being. LeBlond simply tried to make the best heavy-duty engine lathes - and succeeded. The company's only real failings were with the Servo-Shift mechanism and later attempts to upgrade the lighter Regal lathes (that were entirely adequate within their design limits) with what amounted to very large-bore "Oil Country" headstocks. As a sad footnote one of the US Government Arsenals had used LeBlond lathes pretty exclusively for large gun barrel work (naval, tank and artillery); eventually these simply wore out from over 40 years of production use and a decision was made to replace them. LeBlond had gone out of the business, so new lathes were obtained from a German builder, "Wohlberg", and, by all accounts, these were considered to be good machines. They were run in the same service conditions as the old LeBlonds and lasted perhaps 10 or 15 years, some 25 or 30 years less than the originals.
In the 1980's LeBlond had tried to produce their lathes, particularly the lighter "Regal" models, all (or in part) at a low-cost plant in Singapore. This was the last gasp for the company and, when the new owners, Makino, had finished with them, they had built their last proper engine lathes. Unfortunately the patterns, core boxes, jigs and fixtures had all been shipped to the Singapore plant and, when the end came, all were ordered to be burned or scrapped - a decision that precluded anyone from trying to resurrect the machines and once again build a new LeBlond to the traditionally high standards previously insisted upon. That is why we now try to hunt down a good used LeBlond lathe when we need a true, heavy-duty machine to tackle the enormous repair jobs that our power-plant repair shops undertakes. We also run a 60" swing (over the cross-slide) x 24 foot LeBlond heavy duty engine lathe at another of our plants; this beast has a bed 54" wide and turns out toolroom-grade work on parts weighing 5500 lbs and needing 600 lbs of counterbalance weights to keep them stable. In short, there is no substitute for a properly-constructed, American-made heavy-duty engine lathe for those really difficult, larger jobs..

Carriage of 24" x 96" LeBlond NK Series engine lathe. The "pancake" motor for motorised carriage travel and quick return can be seen immediately below the carriage handwheel. A "joystick" lever was used to select the rapid traverse - a feature available on both carriage and cross-slide feeds.