I picked up a mid 69 build date 750 and a 73 drag bike with an early front end from the same estate. The rear wheel and hub from the 69 was on the dragbike are there differences in the front rotor/hub/rim that I can detect in case they swapped the front wheel too?

Square shoulder on the rotor edge? Anything else?
( I just dislike the term sandcast due to the A holes calling everything under the sun sandcast to sell it to people that don't know better. Now I have one, go figure.)