Definitely an Enfield design of hub - that cush drive is very distinctive.
Enfields themselves used this hub of course, and that hollow axle idea - prewar Enfields for some years had sprocket and brake drum on opposite sides.
And being a smaller size of drum, was for the smaller models of Enfields. I notice, for example, the Models B, C, L, LO and G for 1935 had a rear 6 &1/2" drum, among many such examples and years.
The larger models tended to use a bigger drum - which became detachable at some point. HopethisHelps.
