Thanks for the link jackelope. As near as I can tell mine is an Oct. 1948 721. It's got a star, ETT, and a sideways looking cross on the left side. From the link E is October and TT is 1948. The right side has REP and what looks like an 8 on one side of the REP and 88 on the other side. I got the rifle from my dad when I was 14, 31 years ago, and he said it was my grandfathers. I love this gun and now I love it even more.