Max, I have used the tower trainer countless times to instruct someone, some of the guys had there own but some were trainers that were given to me. I usually give them to the student to fly until they get there own plane and gear. I have been borrowing a Write-Wright-Right flyer from a friend that bought it from another friend when it was old so we have no idea when it was made. Parts keep falling off of it and there is as much tape as covering. I had a really old trainer someone gave me, I think, not real sure but it maybe was a tower 40 trainer? I trained 6 new pilots with it until one splashed it on a take off. That was the only trainer I lost due to a crash.
The best triner I ever had was the Sr. Telemaster with an old OS 61 on it.
This Wright flyer I use I have to change the engine when I use the plane. It came with a Magnum .91 on it that was worn out, it was rebuilt but the carb is shot. I was the only one that could keep it running so when I get it I put one of my OS 91s on it.
That trainer I had that crashed has a very worn out OS .40la in it, needed every bit of runway to lift off. Really a hoot in the wind though but rudder sensitive!! Bump the rudder stick and it was headed for the ground. I loved that old beast though.
My Roar is set up stupid, touch the sticks and it will react! I have it on the box and took a friend out for a refresher course last week. The fellow hadn't flown in well over a year, I had to take it several times until he figured it out. I love the Up-Roars!! Ricks thread is in Kit Building on the second or third page and he pasted most of the Roars that the guys were posting photos of during the thread, there are a lot of them there.