I found some information on the round axle from a 1938 British War Office Handbook, Marks IX and X
The early round axle is stamped with part numbers on all items and is identical to the British variant. The detachable stub axles are also the same.
The difference is the wheel hubs, rims, tyre size and the fitting of hub caps.
The wheel nuts have GMH stamps and numbers.
The wheel bearings are going to be replaced because they have Ford script markings
Replaced the brass bushes in the springs and cleaned up the stub axles.
Got a metal spinner to make me a new turntable base cover.