Duster Parts Interchangable?

Ok, I am new to mopars, and I recently purchased a 72 Duster and have been looking for various different parts for it, and was just wondering what years are interchangeable, as far as interior, body panels, lights, moldings, etc. For instance some places I see parts advertised for 71-72 duster, and other places i see 70-72, so please help me out. Thanks, Harley