I put T-Bird seats in my 55 Chevy wagon that look very much like those. Forgot what year. 70's I'd guess. The pattern matched the modified R & P rear seat. I put black carpet in that rear insert to match the backs of the rear seat and wagon floor
Man, I spent a lot of time as a kid lying in the package tray of a 1970 Buick Skylark looking at buttons like that. Those are classic seats.
Thanks I really had no clue I thought about 70 GM but I was not sure . It's been to cold here to go looking in cars