[sharps4590]

I might. Post a picture of the scope and the focus ring and the set screw.

Hensoldt is the maker. They were/are a very large optics firm and made some of the finest lenses in the world, at one time. I have a pair of Hensoldt binoculars and their quality is as good as any out there, even if they are dated.

A bit of history: Wetzler is a town in east central Germany in the German state of Hesse and was a center for optics manufacture, much as Suhl and Zella-Mehlis were centers for gunmaking. Hesse is the German state the "Hessians" came from who fought with the British during the AWI and other conflicts in Europe and Ireland. King George III was of German descent, Hanover to be exact, and was the Electorate, (essentially the king), of Hanover the same time he was King of England and Ireland.

 

[sharps4590]

PRR is correct, that is a focus ring, not an adjustment for magnification. That particular scope is also made for rail scope rings like for a break action firearm. I've never seen any that were removable. It is quite similar to my Schmidt & Bender....and most other German scopes from the era.

You have the right of it, the set screw does lock the focus ring and no, it shouldn't come out, you have that correct also. I'd guess it's just stuck. Gentle and frugal application of a penetrating oil and keep trying to move it back and forth and it should eventually break loose. Obviously don't force it or take a pair of pliers or a pipe wrench to it.

I THINK the rail scope mounting system came about after WWII and I would suspect your scope from the late 40-s through the 50's....and that's sort of an educated, SWAG method guess.