help with barracuda back seat!

I am back to work on a 69 440 barracuda fastback that has been in pieces for 10 years, I narrowed the rear seat back to fit in between the widened wheel wells, and am recovering the seat, the question is what should be on the back of the rear seat under the carpet or was the carpet glued directly to the seat panel? The same with the carpet over the area under the window?