When I started assembling the flap motor housing, I couldn't get the F-785A Backrest Brace to fit. It wasn't even close, it was off by 1/4 inch. I decided to make a new one. Luckily I had some old parts I had planned to use for something else laying around. It's an undrilled EF-601, I believe it is Flap Actuator Channel for RV-6, I put it into position and marked it for trimming.