I don’t know what this bench seat will fit

[1B@d71]

When I picked up my 71’ SB that had been sitting at my dad’s house there was an identical (or so I thought) bench seat in the bed. Same color, same fabric design, same brackets, everything. I thought I had me an extra seat. Come to find out the mounting brackets are narrower than mine and I believe are held down by an additional bolt, but not sure and the seat tilts forward with a small lever behind the seat, my seat does not tilt. My dad had passed away before picking up the truck so I didn’t have any info on the seat. I gotta figure out what it is. Anybody have an idea what the seat will fit?