Thanks Guys, The serial # is 11-82xxx I looked on Rugers website and found that it was made in 1974, 4 years before I was made
Anyway, the grip frame is marked A-100 under the grip, and I tried a Ruger MK2 magazine in it, and it fits and functions perfectly... However, my Magazine will not fit into the shop owners Mk2, So I bought the Mk2 magazine...
I'm very happy with this pistol!
MM454