I measured the gaps between the pre-manufactured F-810A upper bulkhead and the QB skin. (I've mentioned this before -- the gap is up to 1/4" in places. I decided a while ago that I might cut off the existing flanges and make my own, in order to prevent the skin from being buckled and wavy where it meets the bulkhead.)
Tonight I cut 0.040 aluminum angle into eleven 3/4" wide pieces that will attach the bulkhead, and marked where they will go.
I'll think about this some more, and decide if this is the way I want to solve this problem. It's possible I might just make a new bulkhead.