I just noticed that somehow I did not post the details of the struts I used. In the photo you see the ribs that I glue to each side of the strut and the slot that I cut into this assembly to accept the spar. This slot is shown only on one end of the strut assembly. The struts must be then assembled thru slots in the bottom of the top wing and thru the top of the bottom wing. Then the rest of the ribs can be glued to the struts, being careful to align everything with the spar lines. Now the rest of the spar slots are cut. For this last step I needed my wife to hold the wing while I did the sawing. Because of the cutout accuracy required and the many curves involved, I cut the struts and ribs out using a coping saw with a fine toothed blade. It worked surprisingly well.