Although a kit-form gearbox had been designed and marketed in kit form during the late 1940s by L. H. Sparey (author of "The Amateur's lathe"), it was not until 1953 that Myford's first effort appeared. Lubricated by an oil-bath it was designed along long-established "Norton Quick-change" lines with a single-tumbler and a reversible gear on its left-hand face that allowed a quick change between fine feeds and threads. The early boxes (as shown here) were fitted with unhardened gears and (hidden under a rounded, aluminium cover) a pair of external gears on the right-hand face (from which the leadscrew drive was taken).
Later boxes had all the gears inside.
The instruction book for the box is not the same as that for the later model. email for details

Designed in the late 1940s by L.H.Sparey, author of the indispensable book "The Amateur's Lathe" (which we can supply) and a prolific writer on model engineering and model aero engines this screwcutting and feeds gearbox was produced in advance of Myford's own in 1953 - with a surprisingly large number appearing to have been constructed by enthusiastic owners. The box economised by using standard Myford changewheels.