RW@:
According to my records there was only one revolver produced in Germany with the description you indicated.
This revolver was the Frontier or Western Model 2/59, by J.P. Sauer &Sohn Gmbh, Eckenforde/Holstein. It was produced in the 22 LR Rimfire or 22 Magnum Rimfire. It was copied from the Colt Peacemaker, and this gun has exchangeavle cylinders. The Model 2/61 is identical, but chambered for .357 Magnum, .44 Mag or 45 Colt. The model 2/64 is a Model 2/61 with adjustable sights.
HJN