It is an A&D Action Body sporting weapon more than likely made in Suhl with components from Rheinmetall, who had a hollow cavity/vessel patent sort of like Whitworth's where he drew tube steel, along with Wetzlaub & Jagd. engraving and I bet by Richard Keller. It may date from 1903 - 1912 if Eagle Nitro stamps aren't present.
I wonder if this Heinrich Keller is the son of engraver Richard Keller on Krause's site:
http://www.altejagdwaffen.de/Details.155.0.html?&no_cache=1&L=1&tx_fwwcat_pi1[showUid]=156
(Page II Nr. 206)
Kind Regards,
Raimey
rse
