Unertl target scope is about all I know. Not sure if they had particular model numbers or not. This one is a 10x and 22" long, came with the original wood box as well. Unertl mounts as well, pretty easy to install on the gun too.
There is supposed to be a recoil spring on the scope, but it never came with it. Someone told me that some scopes never did have them from factory, not sure how true that is. Also missing the eyepiece lens cap.
I'm a sucker for the look of the Unertl/Fecker/Lyman target scopes. This one is surprisingly clear to look through. Perhaps it will help me get into the 50 metre challenge.....