Talking about pre-war Heym rifles by Adolph and/or August Heym

From Mike Petrov -

** Friedrich Wilhelm Heym **

This company was founded in 1865 by Friedrich Wilhelm Heym in Suhl, Germany, who specialized in made-to-order higher grade guns. The Heym family had been involved in gunmaking from before 1750. In 1912 the business was taken over by F.W. Heyms son Adolph and in 1920 the business was passed from Adolph hands to his son August. August Heym was a master engraver as well as a good friend of American custom gunmaker Robert G. (Bob) Owen. Bob and August kept up their friendship via letters and on a least four occasions Bob visited August in Germany. Bob Owen Jr. still remembers the letters from August Heym as being signed Best Loves, Augie. I believe that some of the parts found on Owen sporters like the hinged floorplate were made in Heyms factory. I have seen several Owen guns, both shotguns and rifles, that I believe were engraved by August Heym. Some are signed with Heyms name, others are not. At the close of WWII August Heym was imprisoned and tortured by the communists. Within a few days of his release he, along with his family, escaped to the Western Zone, and was followed by a few workers from his old factory in Suhl. August started a new company in Ostheim, Bavaria then followed a move to Muennerstadt, Bavaria. Heym produced air-guns, in West Germany until 1952 when he received permission to restart firearms production. Five years later the town built Heym a factory. Rolf Heym, Augusts son took over the business in 1963. In 1996 the company moved to Glecichamberg, Germany, twenty kilometers from the original factory in Suhl.

This gun is very similar to another custom Springfield rifle with serial 5858 AH - same sights, etc. but extensively engraved.

From my limited research - but I still don't have approximate year of manufacture ?
Regards,
Joe V.