Yes i had a Triumph 2500 in the late 60’s with leather heated seats. So they’ve been around yonks. I used to love them in winter especially as it took old cars much longer to get warm then these days, plus winters then seemed a lot colder.
I had the poor man’s version in a 1965 Triumph 2000 with leather seats but not heated, but then I was young and healthy and could stand the cold. ?