Steve, if your Weaver is stamped simply "K2.5", "K4", or perhaps K-2.5, K-4, it is an early pre 60 model. The sixty series have "60" in a box after the magnification. Then the 60A and 60B are so marked. The very first K2.5 and K4 had uncovered adjustments like the old 330, the first modification was to use screw on caps but the optics were not changed. Then the sixty series and later scopes came in. The Weaver repair service used to send out a little card with the various series noted, but I can't find mine.
