Although built very much along the lines of the early Drummond "flat bed", and looking at a glance very much like one, this lathe exhibits a considerable number of differences: the bed differs in almost every cosmetic detail of line and angle, a conventional tumble reverse assembly is fitted - unknown on early 3.5-inch flat beds - the tailstock is of a completely different appearance, the changewheels are of a finer pitch, the T-slots in the saddle run parallel instead of across the bed ways, the top slide  carries a micrometer dial and the arrangement of the compound slide rest feed-screw support brackets completely different.
It can be safely assumed that this is not a Drummond lathe--but one built to closely mirror its design.
Additional pictures here