Manufactured in Germany by Rebmann GmbH - Dreherei und Apparatebau in the Black Forest from the early 1970s, the "Boy" lathe was made in at least two styles - early with rounded styling (and exposed, unguarded drive belts) and  later with pronounced angular lines and covers over the pulleys and drive system. Although it appears that the early lathe was offered in just one size (60  x 200 mm) the later version were offered in three: 60 x 250 mm in Models A (non screwcutting) and B (screwcutting); 80 x 350 mm in Models C (non screwcutting) and D (screwcutting) and 120 x 500 mm in Models E (non screwcutting) and F (screwcutting). The latter machine (of which few can have been sold), was relatively massive and, fitted with a 750W, 3-phase/400V-motor, obviously intended for serious work in a professional workshop.
By the late 1980s Rebmann had stopped production - but were still offering spare parts, collets and tool-holders, etc. At one point the lathe  was being distributed by the "Westfalia" organisation (later better known as specialising in cheaper tools from the Far East) with a 1975 leaflet describing the machine and listing a dealer as: Boy-Universal Kleindrehbänke, J. Brauer, 4050 Mönchengladbach 1, Paul Vaterstrasse 10.
Although a small and simple lathe and so presumably (in the two smaller sizes), aimed at the amateur market, the lathe came with an approval stamp from the German Institution for Statutory Accident Insurance and Prevention, a classification only required for professional equipment. Hence, it was not unusual to see the lathe installed in the workshops of electrical and electronic companies who needed to make the occasional mechanical part or undertake a repair.
Of straightforward and particularly economical construction, the lathes used standard metric threads throughout. The bed casting was heavy,  just under 20 kg, with the large feet cast-in and wide, flat ways supporting a carriage and tailstock that shared the same central slot for their alignment. The M12 leadscrew ran down the centre of the bed, below the ways, with an ungraduated handle at the tailstock end to propel the carriage up and down the bed.
Both cross slide and top slide were formed with their feed-screw end plates cast integrally (the top looking rather like that on a Myford ML10) and fitted with usefully large-diameter handwheels. The cross slide ways were wide, and deep, but close together with the degree graduations on the rear of the top slide being rather widely spaced.
Keeping to the theme of simplicity, the 3-step, "Z" section headstock pulley was overhung on the end of a spindle the front of which ran in a plain bronze bearings with the rear a roller race - this arrangement (of an overhung pulley) having been proven on both expensive - Pultra - and many less expensive lathes - for example EXE - over many years. Unfortunately, the lack of a proper backgear severely restricted the lathe's low-speed performance, thought at least the design did allow an owner to bolt on an even larger spindle pulley and so obtain a more useful and slower bottom speed. On the screwcutting model the pulley was spaced out and a gear carried on the end of the spindle that drive down to a train of gears fitted with a tumble reverse mechanism -  this sliding feed to the carriage being a most useful addition to the lathe's specification.
Threaded M24, the tailstock spindle screwed directly into the casting and locked (crudely) by an ordinary screw that bore down against it.
Late Models
Later, angular-styles model enjoyed some changes: they were fitted as standard with a larger diameter drive pulley that gave, by reversing the motor pulley a range of five reasonable speeds: 290, 520, 630, 900 and 1150 r.p.m. A reversing motor was standard and the degree graduations of the cross slide moved from back to front - though they were still far too widely spaced to be of any use. Although the front of the spindle still ran in a cylindrical bronze bearing this was made conical on its outside to allow for adjustment as it was drawn into its tapered seat. The end of the spindle was supported by a roller bearing with the end float taken out by adjusting the clearance between pulley and end flange.
If any reader has a Boy or Rebmann lathe of any type, or information about the company, the writer would be interested to hear from you.
rebmann.de may still have some spare parts for the BOY Lathe..