Installed both F-1204R retainer blocks on forward bulkhead side assembly and center section (page 20-02, steps 2 and 3). Attached F-1204P-L & -R skin attach flanges (page 20-03, step 7). Riveted F-1204D center section aft bulkhead and F-1204F-L & -R aft side bulkheads to F-1204 center section. Also, matched drilled and riveted F-1204T-L & -R skin stiffeners (page 20-04, steps 1 and 2)
