Drilled aileron counterweight strike plates' rivet holes. Riveted in the final top skin stringer (L channel) holes. Had to widen the aileron counterweight hole (bottom part) a bit more so the counterweight can hit the lower stikeplate. Trying to figure out how to mount wingtip panels. They seem too short. Will email Zenith tomorrow. If I move them full forward so they are tight in the leading edge, they are too short in the rear. If I move them so they are flush in the rear, then they are far too short in front. Did some research on the Zenith builder forums. Found out that this is a common issue for which people have been asking Zenith about. Said they had redesigned the wingtip (or maybe the end of the wing) and therefore they aren't always fitting. Some even cut their wingtips into two peices.