Photo 1 shows how I grouped the wing ribs to mark a center line using an aluminum tube drawn across the top surface with the ribs laying flat on the table.
Photo 2 is a view of the trailing edge spar lift strut attach brackets temporairly installed. This is how the wing should look with the proper layout for building up the wing. Make certain you know which side of the wing is which BEFORE you do any drilling. If you don't you will drill on the wrong side, and the wing will be ruined.
Photo 3 is the same view from the opposite direction.
Marking rib top center lines
Trailing edge lift strut attach brackets as viewed from the wing tip.