Jim, What about to change modulation and pitch bend wheels? They seem to be quite similar.
Miro
Looking in the service manual, the Mod Wheel and Pitch Bend circuit boards are exactly the same size and layout, right down to the size and position of the mounting screw holes. It even looks as if you could swap them over without unplugging the cables from the boards first.
So assuming that the case cut outs are the same for each wheel, it should work as long as you don't mind the legends on the panel being wrong!
In fact it looks as if the most difficult part would be removing and reassembling the lower case which involves an incredible 45 screws!
This is an old thread, but for anyone with a similar problem, who is confident with opening the case, then I would think it is definitely worth a go.
Excellent idea Miro!

Regards
Ian