Need Help-What are these bucket seats?

Forgot to mention another confusing item. When I bought the Duster it had the little flip up "Buddy Seat" stuffed in between the bucket seats. Upholstery looks to be the same and about in the same condition like it was all pulled out of something else at the same time. I thought the Buddy Seats were a B Body option? Anyone, anyone,,,, Bueller?