Yeah, the early, vintage USA Weavers are functional scopes, but the import models, especially the early ones, are not in the same class by a long shot.
Lots of K4's, T10's, etc, are still out there and functional, 40 yrs later! I have a K12 on a varmint rig that went on a FTR rifle for awhile and never bobbled.
Some of the Target scopes still sell for a premium!!!!
The glass is 1960ish and not in the same league as modern, top shelf glass, but still entirely suitable for most hunting.
I do not own any new Weavers, but hear the newer imports are better.