Hi, I'm Paul, flying models in Belgium, Europe. I found this older topic by a google search about my own Cap 21.
I think I actually own a Cap 21 which once belonged to hr. Hoppe. The model was rebuild with a G-62 and a Tony Clark exhaust and hydromount. You can find pictures in this thread;
http://www.rc-network.de/forum/showt...503-TOC-Cap-21