Due to already having to replace the F-710B angle once and having to upsize to -5 rivets, and the fact that one of those is a figure eight, I decided to replace the F-710 bulkhead. I fabricated a new F-710B HS attach angle but left it with a slight interference fit and will refine the fit after replacing the bulkhead. Removed rivets securing the F-710 bulkhead from the longerons down to the bottom J-stringer on both sides. The rest will require either working from under the fuselage or rolling the fuselage over.