Space Duster seatbelt question

My '74 Duster with fold down rear seat has a 2 + 2 seat belt arangement, does anyone else?

The 1974 Duster / Valiant sales guide states 5 passenger seating for a Duster and 6 for the four door. No reference to a Space Duster being any different.

It is very possible someone removed a set of belts from the front bench seat, the rear seat was never removed from the car till I owned it.

Fellow Space Duster owners have any thoughts on this? The build sheet is no help either.