Starter contactor arrived today, so I mounted it to firewall and fabricated from 2awg wire connection to firewall pass-thru.
Decided on transponder antenna location under left seat. Drilled and deburred holes into fuselage floor.
Carefully wedged myself into tailcone. Changed seat belt attach mount bolts to non-magentic bolts and nuts. Sits within inches of both compass modules. Also installed rear seatbelt cables.