Welcome! Glad to have you aboard. Both the rudder and elevator horns on the Gee Bee are made of 1/16" ply, epoxied to hard points I added. Nothing special, really. I added 1/16" balsa pieces inside the fuselage to support the 1/16" wire pushrods.
I'm not exactly married to Tritle designs only. Although I like most of his subject matter, and the Dumas kits seem like a good value, Lots to choose from there. I'm also looking into Easy Built, among others. They have a 40" Monocoupe 90A I've got my eye on. It doesn't appear to be very scale, though. Honestly, As I've said before, "So many airplanes, but only one lifetime."
The Rascal is coming along slowly. I think I've got one of your dead turtles working on it. Ha!