The "old" Weavers, that are desired by some shooters, and carry some value in certain models, are the "made in USA variety" . If yours is not USA, its an an import, and the new Weaver company (?) may work on it.
If you send a USA Weaver to the new Weaver people they will NOT work on it. But.....there is an outfit called "Ironsight" which overhauls vintage USA Weavers (and Redfields). The wait time is high, over a year, but you will get a sustainable, useable product back.
Look on Ebay, under vintage or USA Weaver scopes and you will see a fair collection of old Weavers.
The USA weavers were steel tubed and had a tough adustment sytem. Their 1960-70's optics are not the equal of USA scopes today, but are good enough for lots of hunting and some guys still love'em.