A Sauer example wearing 61xxx would have been issued a serial number circa 1896 and the >>Not English Make<< was used between 1925 & 1955, if my memory serves correct. So the longarm was more than likely a War Trophy taken to England and per law passed thru the Birmingham proof facility due to a lack of reciprocity between England & Germany. Lots of British Chicken-Scratchin' to sift thru but it appears that the hammer double wears the Sauer Quality Crown.

Cheers,

Raimey
rse