They are 81. They were sought after back then mainly because they offered quite a bit of adjustability over the OEM seats which only moved back/forth...no tilt. The cars would get stolen and recovered with the seats gone.
Recaro offered them aftermarket as well specifically for a 2nd gen but I don't recall two tone other than what came on the Recaro edition Trans Am.
I bought a set new-never bolted in for my 2nd gen. I bought them from the original purchasers son who's father had passed. His dad bought them in the 80's and they sat around since. He never got the car back on the road.
Here's a pic of my 30+ year old/new seats. I had to swap seat brackets due to my different early floor pan.