Maybe this gun started out life as one similar for sale on the Simpson LTD site...the Swiss cross/sunburst on the chamber is interesting along with the "germany" stamping.
This one has the Artillery "notch"...maybe a left over receiver from the end of WWI.
A receiver with the Swiss cross/sunburst could indicate a left-over part from the M1906 Swiss production run...
http://www.simpsonltd.com/product_in...oducts_id=2268