Layered poster board over the F-704 carrythrough spar bulkhead and the F-705 rear spar bulkhead. It may be hard to see, but note that on the inboard facing flange of the F-705 bulkhead, I've layered an extra layer of poster board to make clearance for the forward flange of the baggage area cover that attaches here. The screws used to attach that cover will also be used to attach my interior panel.