RE: Midwest Tri-Sruire
Great to see a post about this plane. I learned to fly on Tri-Squire with an OS 19 and Heatkit GD-19 blue box back in 1971. I started with 3 channel then added strip ailerons. It was covered with Monokote.
One was just sold on Ebay for $76. I would have liked to have had it for nostaglia's sake but didn't bid seriously enough on it. The pic is mine back in 1971