Parabola,
It was not Ernst Schegelmilch that worked at Spandau, helped set up the Arsenal at Kabul, and developed the "Schegelmilch" action; instead that was Louis Schegelmilch. The extended family Schegelmilch has been involved in making guns in and around Suhl/Zella-Mehilis/ and Spandau for many years and I would guess it still is. During the 1970s and early 80s my friend Alfred (Fred) Schegelmilch was working at the Firm Heym during the week and in my gunsmith friend Walter Grass' shop on the weekends and holidays. I never met Fred's son but heard Walter and Fred talking about him working to become a gunsmith also. Based on his age, I'm guessing he is still involved in making guns and maybe has children also involved. Over the years, I have seen a few Schegelmilch guns advertised, maybe even yours. Because of my friendship, I take note of the name when I see one.