I have a J.P. Sauer Mauser rifle with the Sauer serial number on the side of the receiver ring and the Mauser serial number behind the recoil lug. What makes it very unusual is the fact that the Mauser number is 2003, which makes it a transition model action and one of the first released to the civilian market, since the first 2000 went to the German military.
It has a half round, half octagon barrel with integral full length rib, caliber 8X57J, and a typical pre World War I stock with side panels and a cross wedge with escutcheons in the forearm. The wood has been refinished and the bolt handle and safety altered for low scope mounting. I took two deer with it last season.