Interior parts interchange? 1973 vs. ??

I have a 1973 scamp.(2 door). I need to replace the back seat cover and the door panels. What models are compatible with this. For example, when looking at Legendary and Classic industries, Sometimes they list compatibility with Dart Swinger or Duster or dart sport coupe. Something like this.
Yet sometimes they only include Scamp or valiant. When searching for parts, the scamp is harder to find than the dart models.
My question is.... What models are compatible for interior parts for the 1973 scamp and what other years can I search for that may be compatible? I read that some earlier years were possible. Some are not..

For example, Arm rests for 1968-1972 are listed as different than the 1973 to 1976. but the carpet is the same for 1967-1976.. So confusing... Is there any parts exchange list for the A-bodies. Right now, I am looking at interior parts, upholstery, carpet and such..

Thanks for any guidance..