Dean, Smith and  Grace Type A and B lathes from the late 1930s and into the 1940s (marked variously as A, B, 4AN, 4AV, 4BN, 4AB, 4BR, 4AR, 4ABR, 4BDR, 4BZ, etc). These lathes had simple lever control of spindle speeds together with pick-off gears inside the headstock for which instructions are given.