Set center section down on the bench. Install outer ribs loose and set with gauge (no glue). Rough fit inner wing tubes.
Install next rib loose against inner loose rib at angel already set and clamp together , adjust slots in spars for best fit.
Ignore what the outside perimeter of the rib is doing.
Set up outer wings at proper dihedral and begin to shorten the spars untill the wing and center section come together.
Finish fitting wing tubes with no force on them, you should be able to rotate them in the holes then tack glue parting ribs to spars.
Glue tubes into position .
Slide outer wing away from center section and finish gluing parting ribs.
Block sand parting rib profile using wing profile as guide.