As far as modelling is conserned...there is no difference in a 232 and a 231ex. On the full scale version, the only difference is the builder of the wing. I can't give you the years, but the Cap 231 was built, and then Mudry put an Extra's wing on the fuse of the Cap231 and called it a Cap231ex. After that, Mudry built the plane and the wing just like the 231ex and it bacame the 232.

Bryan