A mystery lathe from Australia - the background to which is unknown, but obviously intended for sale on the amateur market and marked on its bed as the "GEM Mk. 1".
Built with simplicity and cost in mind, the headstock would almost certainly have contained a pair of ball or roller races, the spindle being driven by a 5-step V-pulley overhung on its left-hand end.  This simple and effective method (in place of a pulley between the bearings) relies upon a rigid, box-form headstock and can be found on numerous machines including watchmaker, miniature, small and medium-sizes lathes - those coming to mind including the original Emco Unimat and later Unimat 3 and Compact 8, the Lorch Triumph and Hobbymat, the American Machinex, Logan, Hamilton, and Clausing 200, the English Hector, IME 100/300 and EXE and French S2F Lyon Cordima and S.O.M.B.V.
Flat-topped and with V-edges to guide the saddle,  the bed had a central, vertical-sided central T-slot to locate the tailstock and a usefully large, fixed gap. The cross slide benefited from an extension bracket at the front to carry the cross-feed screw - so giving the slide greater travel when used to carry a milling slide - and a simple top slide with a single bolt upon which it could be swivelled.
Screwcutting was by changewheels, the drive passing through a dog clutch at the headstock-end of the leadscrew - and hence connection to the saddle being by a full nut, the arrangement meaning that much twirling of the leadscrew handwheel was necessary to reset the carriage feed after a powered cut.
The maker appears to have provided a proper countershaft, almost certainly cast in aluminium, with a motor mounting built on.
Should any reader have a Gem lathe - or access to Australian Model Engineering or similar publications from the 1950s (and, just possibly) the 1960s, where may be found therein a small advertisement for the lathe, the writer would be pleased to hear from you.
Links to other Australian lathes can be found here.