There is a skin that covers the fuel tank, it is held in place by 80 some odd screws (into nutplates.) I used the first wing tank cover as a master for the second one, which ended up to be a mistake. I made the second cover by copying the size and screw hole layout exactly to a new blank I had cut it out of 0.032. Everything went to plan except I did not double check the lower flange of the false spar on the second wing in comparison to the first wing. The second wing flange was slightly shorter, not much but enough to create an edge distance issue for the rivets of the nutplates that would hold the cover in place. We are talking 0.015" but enough.
After cutting a second blank 0.250" longer I again copyed the top and right side screw hole layout, drilled the skin and clecoed it to the wing. There is now sufficient skin to layout the screw hole locations with sufficient edge distance at the aft false spar.
I will mark the locations of aft (lower in the photo) and inboard ribs, pull the skin and drill the screw holes.