What do I need and what do I don’t!

You will need a factory manual that has the complete wiring harnesses. The "Seatbelt interlock system" Has 17 wires that I removed to start with.
Remove the AMP meter wires from the meter and secure them together. This will eliminate the major fire starter.
I will forward a copy of color codes that go to the firewall connectors which will give a starting place.