The above photo shows 1/2 of the wing, the spars extend just under 3/8" beyond the first rib to leave room for the engine pod to drop into, the bottom center section has been sheeted with 1/8" ply..
The first rib is 1/8" ply, the next rib is (2) 1/4" balsa ribs side by side and the spars will be cut between the 1/4" balsa ribs to make the center wing section.
The ribs at the front spar section has been removed for the wing joiner to fit into, also the front portion of the 1/8" ply rib will be cut off, I built the wing using full ribs to aid in alignment of the wing construction.