Laid out dimensions for the front backboard on sheet of plywood and cut it out. Installed the backboard in the fuselage. Straightened out the F858 shoulder anchors so they would lay flat against the skin, then filed the ends where they overlap the tabs on the bulkhead for a flush fit. Clamped the F869 gussets to the upper longerons. Match reamed #41 the aft top skin to the bulkheads and to the F882 canopy rail receptacle. Match reamed #30 the skin to the shoulder anchors.
Backboard installed in fuse
Skin match reamed to bulkheads and shoulder anchors