Eurekame2,
yep built everything - I planned on using the 80/20 rail for the wing drill when Ifirst started this project, way before Iconsidered it for the frame - just happens that Idid the airframe first. Wing tube is a much better idea. Iset the sleeves in the wings this afternoon and added 1/4"thick plywood pads inside the fuse to reinforcement the wing tube holes in the side plates - these additional plates allow precise alignment of the wing tube parallel to the top of the fuse, and for perpendicularity to the centerline (wing tip diagonals back to the tail).

If anyone's interested in having their cores drilled for tubes, shoot me an e-mail.

Thanks!