Part Number: 104520-21 (Second observer seat assy) Part Number: 104520-22 (Second observer seat assy) Part Number: 104520-3 (Seatl) Part Number: 10452030 (Component) Part Number: 104520-5 (Second observer seat assy) Part Number: 1045-2-0587-0B-00 (Socket burn in t/h) Part Number: 104520-6 (Second observer seat assy) Part Number: 104520-7 (Seat second observer) Part Number: 104520-9 (Second observer seat assy) Part Number: 104-520-9001 (Switch actuator) Part Number: 104-520-9002 (Actuator) Part Number: 104-520-9003 (Adapter) Part Number: 1045-20-A (No description) Part Number: 104520RE21 (Nut)