Some parts will interchange like engine cylinders and head. You will need to use ZA rods and pistons though. Fuel tanks and hoods are different The rear wheels, if they are the same as our RTU wheels, will not fit the ZA hub. They have a different flange(see pics). First pic is a ZA wheel and hub. #2 is an RTU wheel that happens to be on a John Deere, but shows how it won't fit over the hub which is the same Diameter as a ZA. #3 is our RTU hub with a ZA wheel on it. You can see the gap around the hub. Hope this helps a little.
I should add that the RTU's were changed around 1950 and I'm not sure if the hubs and wheels were updated at that time so I would check to see what the wheel center flanges look like.
I should add that the RTU's were changed around 1950 and I'm not sure if the hubs and wheels were updated at that time so I would check to see what the wheel center flanges look like.
