Knollmorgen Optical Corp. made excellent products and supplied periscopes for the Navy. They were also involved in the Norden bomb sight. The wanted to keep their skilled workforce after WWII, so they entered the rifle scope business.
These Bear Cubs have 26mm main tubes, so don’t try to put them in 1” rings (25.4mm) or you’ll damage the tube. 26mm rings are a bit difficult to find, but they are out there. The optics on these scopes are excellent and mine are still clear and bright after 60 years or more. I think the lenses are better than the later Redfield’s, which had an issue with the adhesive that held the lens halves together drying out and clouding.
Redfield bought out Kollmorgen, which explains the striking resemblance. I currently have 3 variations of Bear Cub scopes. I may have another mounted on a gun, but I’d have to look.
The top is a 2-3/4X marked Kollmorgen.
The middle one is a 4X “Double” marked Kollmorgen - Stith Mounts.
The bottom is an early Redfield 4X Bear Cub.
The value depends on the condition. A really nice Bear Cub can bring $200-$300 to someone who knows what they’re looking at. Kollmorgen also produced a 4X with larger click knobs for windage and elevation that was used on the M1C sniper rifles. These are quite scarce and can bring thousands of dollars.