Not sure of the year, must have been 82-83 ish. At the time a lot of people had Uni seats but the ACS one was a bit more comfortable to sit on. My one has been well used and I had to re-rivit the seat onto the post, file and polish all the digs in the seat itself and the post. It seemed better than a Uni in that it fitted properly on most bikes as well and you didn't have to use a shim.
I don't remember seeing another back then but I think there are a few pictures on here somewhere.
I actually restored that bike about 15 years ago, just wish I had looked round and bought some new brakes for it at the time as I bet there were loads around, oh well.