Bucket seats for Duster

Good luck! I did the same search about a year ago. First there are no aftermarket seats available. Second you will need tracks that fit your car, 70-72 Duster/Demon. I don't know about the Dart/Swinger stuff but it is probably the same.

Mopar used the same "high back" bucket seat frames in the 70-72 A-body and 69-70 B body cars. Start searching for those parts!

Replacement upholstery materials are readily available.