Deburred, dimpled and countersunk all F-825-1 aft top skin holes. Applied a bend to both sides of top skin. Countersunk L&R F-858-1 shoulder harness anchors. Deburred, dimpled and countersunk L&R F-869 gussets. Removed all bulkheads and attachments. Deburred, dimpled and countersunk all bulkheads. Rivet F-808, 809 and 810 bulkheads to fuselage. Rivet F-807D harness fairleads to F-807B-1 bulkhead.