They were nice scopes in their day. It was basically a Unertl knock off. One of the problems with those scopes and similar ones from that era was that the sealer around the lens "cells" would dry up, crack and let the water inside evaporate or leak out. This would leave behind a funny looking white stain that wont clean off. You can still look thru the scope and it has nothing to do with it holding zero, but it does knock the value down. many people don't even know to look for it, much less how. First, clean the lenses real good. Hold the objective end pointing straight up under a light source. Try to look across the lens at as much of an angle as you can and still see the surface of the lens, if the ghostly white stain is there then a cell is compromised.
These scopes were intended for use as a daylight target scope and while many people use them to hunt animals like woodchuck, the scope will not perform very well at dusk/dawn times. The lenses were unquestionably some of the best optical grade glass ever used, but the coatings were not really there yet. Well, at least not in American made optics.