By 1945 the Delta company had been sold by its founder, Herbert Tautz, to Rockwell, and, happily, that company seeing potential in the design, continued the development of the original wood lathe and turned it into a rather more sophisticated and useful machine. The bed was now constructed in cast iron and a proper, enclosed headstock was fitted with the multi-step V-pulley running between the bearings rather than being overhung as before; the drive could also be taken either downwards, as illustrated in the picture below, or rearwards so allowing the owner to choose the most effective drive system for their particular installation.
Running in sealed-for-life ball bearings, the spindle was bored through 11/4" and carried a 1-inch diameter, 8 t.p.i thread at both ends - the left hand one, for bowl turning, being "left-handed", of course to tighten automatically against the tool thrust.
When driven directly from the motor, four spindle speeds of approximately 915, 1380, 2150 and 3260 were available, but, if the owner wanted to undertake light metal-turning work and larger wood bowl turning, then it was necessary to employ the optional countershaft, the use of which reduced the bottom speed to a more user-friendly 340 r.p.m.
A range of handy accessories also became available, including a very unusual "two-thread" faceplate that could be mounted on either the right or left-hand end of the spindle. The faceplate was not, as might be expected, machined with a separate thread on opposite sides, instead the left- and right-hand threads were actually combined, the multiple starts of each thread interlacing with each other as one would interlace the fingers of both hands. As one holds the faceplate and turns it, looking down into the threads, the threads are seen to "cross" each other like this twice, once in each 180 degrees of rotation - a most unusual yet effective arrangement (but not, experienced users caution, to get on cross-threaded..…)
Although the spindle indexing device was retained from the earlier models (and more conveniently situated on the front of the headstock) the tailstock had lost its eccentric lock and used a cheaper "through-bolt" fastening used together with the usual and unfortunate "self-hiding" wrench.
By the late 1950s Delta were also offering a range of bigger and heavier wood lathes, some with gap beds and a neatly enclosed variable speed drive and, by the 1970s two up-to-date models 12-ich with mechanical variable-speed drive and a "16-inch" with electronic control" - both the latter sold being sold under the Delta label.
If any reader has good-quality photographs of Delta wood lathes, of any year or type, the writer would be pleased to hear from you..

Late model Rockwell Delta 12" wood turning lathe with variable-speed drive and a detachable-gap bed. Two models were available, the "Heavy-Duty", shown here, and a "Standard" version - which could be had with either the variable-speed drive, or an ordinary 4-speed, V-belt drive headstock, not unlike the one shown at the top of the page. On the variable-speed model the spindle-speed control was a built neatly into the end of the headstock.