Where are you located? You can e-mail these guys or call them to get AMC parts:
AMC 4x4 Salvage
1-800-882-5337
amc4x4salvage@qwest.net
6741 W. Belmont
Glendale, AZ 85303

 

Go to your local library and look at the Kelly Blue Book and/or N.A.D.A. guide for your vintage in the Reference section. One or both of them will show the MSRP when new.

 

My parents bought a 77 Cherokee new and it was in the $7500 range. I bought a 77 J20 over 20 years ago and the title said it was $7200 or so new. Most county tax assessors can look that up for you so they can tax you as much as possible.