72 duster bucket seat foams.

In addition to Alaskan_TA's information, my understanding is that in 72 they started molding the foam right onto the seat frame, so technically, the foam is not replaceable, but there are stories of good upholstery shops fabricating new foam or modifying the earlier foam to make it work. the September 2019 issue of Mopar Muscle had an upholstery article that discussed this foam change.