Correct Super Stock Seats?

I missed the OP opening statement that we are talking of 68 SS darts, cudas. I have an acquaintance that has a surviving 64 Belvedere Hemi car. I guess it is called a super stock? Never tubbed, never raced. I have not seen it in a few months and the interior was not in. Bench or ? I don't know.
Those early B bodies with just the front A100 bucket an no back seat I thought came that way from the factory and were called super stock? And how many "homebuilt" versios of the early B SS were made with whatever? Maybe the B and A cars and homebuilt versions is where the seat thing can get confusing. Anyway interesting info from everyone.
I know Mosher in a Ca. did a lot of restos and builds of early B SS stuff. Not sure if he is even still alive?