70 duster rear seat interchange and what do I look for

Hi my 70 duster never came with a rear seat. I’m going to a Mopar swap meet soon, but not sure what years, models interchange. I’m pretty sure 70-72 duster, 71-72 demon will work. How about 2 door valiant 70-72? I believe dart rear seats will not work and 4 door valiant seats won’t work either., I think I read the 73 and newer duster rear seats were different also. Are there any identifiers, things I need to pay a attention to to make sure I’m getting what I should be. Thank you.

I have a spare rear seat frame for a 70 Duster on the west side of Michigan

IIRC the 1972 Demon seat has a different lower mounting set up than the earlier ones. It bolts in, while the '71 type "hooks in". Found that difference between a '71 and '72 Demon.