Here are the last two Pics of the fuselage...
Top of cabin where wing plugs in
Side view looking into cabin showing 1/8 th" birch ply wing leading edge hold down, it is the black painted vertical bit in front of the spruce and balsa vertical front cabin brace. It goes up and over across the top of the fuselage and down to the other cabin brace. The wing leading edge butts up against it where the wing leading edge hold down dowels plug into. The actual ply piece looks a bit like an inverted " U".
Hope this helps out
Carlos G