I pre-drilled WD-822- (L/R) to remove the powder coat then put the auxillary longerons in place, as well as the F-802S-1 Spacer and F-802D-1 Landing Gear Box Plate nd checked for fit. Then final drilled all the nutplate rivets and common rivet holes on the center section and the mid cabin braces. I clecod the F-848-1 Upper Longeron Gussets, F-845-1 Gussets, and F-846-1 Gussets in place on the Center Section Fwd Bulkhead flanges to check the fit – un-clecoed the center section from the forward fuse and deburred all drilled holes in the center setion/mid cabin braces.