Just wondering if anyone has put together a model A RPU. With a 28-29 cowl. And a 30-31 rear portion of the cab.
I'm sure it's been done. Problem is the body lines won't match. A good bodyman could pull it off. Why do you want to do that? https://brookvilleroadster.com/store/bodies/ Has good side view pictures of both year Roadster P.U. bodies so you can compare them.
If you want the back of a 28/29 cab rounded, do what Barris did on the Ala Kart. Use the rear section from a 28/29 touring. Belt line becomes a non issue.
Last Refuge in Colorado (drop it) has made a sorta combination 28/29-30/31 body for several years. Getting one may be another story for another time!