Wow, I haven't heard of a McCoy engine in long time. I think they went out of business in the early '70s. I've never owned one, but I remember other members of the R/C club running them. There are guys who collect old model engines, I imagine that one would be quite collectible now.
The cadet is a great plane to learn to fly on, I've flown several myself. The last thing I was interested in was flying combat. Had a scratch built flying wing that was a piece of square 2" PVC downspout pipe, with a foam core wing, and elevons. We tow a crepe paper streamer behind our planes about 30' long and then try to cut each other's streamers. This is a lot of fun, but a lot harder than it sounds. The plane mounts a Magnum .36 ball-bearning engine, so top speed is somewhere around 80-90 mph, and it can turn about a 12' loop at full speed. We tried to count the roll rate once, but couldn't count that fast! For solo flying I have a Ultrasport with a .40 and retracts.