Seatbelts---reuse or new?

If there is any fraying of the webbing, replace it. There are a couple of companies that will replace the webbing using your hardware. The guys I knew from my aircraft days won't do cars because of liability issues.

I agree with others that the separate lap and should belt arrangement was not a comfortable solution. Since the interiors on the 72 and the 73 are black, I have used shoulder belt sets from later model full size vans and pickups (which are usually black rather than color coordinated with the rest of the interior). If you decide to go this way, you will need a T-55 (I think)Torx bit on a ratchett to get the mounting bolt out.