I don't think GSA converted anything other than the 1911s.
Yeah, that's one of our mounts. I really like the one in the photo. My Dad developed load data a long time ago for the .308 conversions and man that rifle is a shooter. They seem to show up at gunshows, so it you do find one, buy it. You won't be disapponted. The sellers very often don't have a clue what they are.

Latigo