Made 2 stiffener angles, match drilled to Fwd Center section bulkhead/spar. Cleco mid seat rail supports together and match drill, Then cleco to Center section bulkhead, and match drill.Cleco the left and right Bulkheads to the center section and match drill all #30, match drill #12 all common an 3 bolt holes between clecoed parts, countersink nutplate holes on all parts.
Stinnener angle brackets match drilled
Mid seat rail brackets & L&R bulkheads clecoed and drilled