How much is a rear seat option for the SA/FB worth?
I have one and curious to its value. New upholstery. It's grey, dunno if that matters or not.

 

They're generally worth upwards of three digits ($100+) to the right buyer. They're rare and kinda cool. I've only seen one car with them installed and it was kind of a cool thing - but a waste of space in my opinion. No one can sit back there that's over 4' tall.

Throw up some pics!

 

 

I've got some rear seats too that came in my 79 limited. Post up if you sell them and for what for

 

You can ask top dollar if you have the side panels and seat belts that were sold with it

 

I have the side panels but not the seat belts.

 

That seat does not look OEM to me. I had a back seat option that I bought from Australia and it's nothing like that.
The shapes in different areas are not right. There is no opening in the middle for the buckle to come out through.
And there were no gray interior first gens.
I think that you have a fabricated seat.

 

looks right to me, looks just like mine. granted mine is 79 limited from canada land but looks the same. just diff color

 

I had a red leather one with side panels but no seat belts. I sold it for 150 plus shipping from southern ohio to southern canada. Mine looked just like yours it was not a mazda part it was made by pacific avatar which makes them a little hard to find.