question on 73-87 ? low back tuck buckets

[MAC67]

hey guys was rummaging through a local yard here in shelbyville and came across about an 85 red gmc short bed with a set of lox back bucket seats in it that looked like they fit like factory , i dont remeber ever seeing one these trucks with buckets in them , they look alot like a 67-72 truck bucket seat , they are low backs with one small little square chrome right in the center of the seat about an inch high , whats yourt guess could they be 67-72 or would they possibly be from a later year truck >?