The braces on the outsides need to be bent more into a curve to match the curve of the skin. I did this with my hands until the brace laid in place pretty well. The edges have to be bent similar to the middle brace so they fit on the flange of the frame and up against the top skin.
Plans say to drill the braces to the frame. And to level the frame. I drilled first just the holes of the braces to the flange of the frame. Then . . .
