1973 Duster wiring harness compatibility question

It should, the only differences might be the ignition setup (electronic) and alternator so check those.

To be honest there's quite a few good new wiring harness options out there which are priced really well. I'm rewiring my entire 75 Duster using the EZ Wiring harness ($185) and it's well worth it. American Autowire has an entire connector to connector harness for $799 if you don't have a lot of electrical experience.

Why replace a dry rotted 1973 harness with another 1973 harness that's gonna be there soon?