a little help w/67 backup light wiring

The pin continues to move with the shifter so the switcth makes the contact in the reverse position only. Before and after that position the switch should be open. Bottom line, your switch is good in the contact sense. Wear in it could have contributed to the pins breaking though.
If I was replacing that pin I would replace the switch too.
If you have installed a later model automatic trans you could forget all of that and simply route the 2 wires to the trans mounted switch.