RE: Shark XV .15 speed plane?
Hummm... The wing looks like it could use more structure. I'd worry that if you ever got the thing up to speed it might flutter. A D-box leading edge and more wood on the TE might be needed. I don't see any vertical grain sheeting between the spars either. If the rest of the plane is that light, you might be in for some work before you get it up to speed. It really hard to tell from the picture though.
Bill