Krupp Stahl- Krupp Steel-- first German made sporting gun I have yet seen with just that wording- usual steel grade might be- Krupp Special Gewehr LaufStahl- Krupp Special Gun barrel steel- of all the nickel bearing ordnance barrel steels of that era- Krupp was the best for machineability- damn good steel!~!
Otto Bock guns were often made for export, some of the stampings you have found for us indicate that this piece was made for export- possibly to Stoeger in NYC- a firm founded by Good Germans that later became America's Gun house- back in the days when you could order a M21 skeet gun for a few C'notes and have it shipped RR Express right to you- No BATF 4473 forms, etc-
Are there any markings on the scope bases- inside the dovetails? On the forearm inside- usually on the forearm iron. I may have a horn buttplate to replace the broken one on your gun, but would need dims from the existing one to be sure- Fine gun, as are/were all the German and Austrian Sporting guns!
