[rich b]

The '48 axles are both too wide. The spindles, brakes, and wishbone can be split and used (if you don't mind the dog-leg in them.

The rear brakes are usable along with the shorter rear wishbones. Maybe the '48 rear will have a better ratio and you can swap out parts in an earlier '38-'40 rear.

The '48 box can be used for cross-steer with a little work.

Probably more things can be re-purposed with a little figuring.