I just sold a "quality" Redfield 3x9x40 like the one you describe on eBay for $60. Was just updating my Optics.
I gotta tell you I echo everything what was said above. Even a cheap $99 Weaver Nitrex will blow it out of the Water Optic wise. It's,like,you want to wipe the lens clean because you think there is film or rain on there.
I sorta get wanting to keep a classic look. But yet I don't.
Even my Vintage Leupold Vari X III of all things don't seem nearly as clear or as sharp as my Leuoold VXR or VX3.
Glass has come a long way in 15 years,. Go back 30 years and you reall have a relic. Sure it will function but damn.