Note: I debated whether or not to use the Nazi flag in the thumbnail image, and opted to put it in there because it was in fact the German flag when this pistol was made. It is a powerful symbol, but hiding the symbol does not do anything to change the history that has occurred, and I decided it was better to acknowledge it than to hide it.
Anyway, this pistol on display here is a Sauer model 38H (a much more common pistol in German WWII service than many people realize) that was made specially as a presentation piece. Heinrich Himmler presented these pistols to snipers who had killed 100 enemy soldiers - other prizes were offered for 50 (a leave from the front and a nice watch) and 150 (a hunting trip with Himmler himself). For 100, it appears that a sniper was given a choice of binoculars, hunting rifle, or these pistols.
How many were actually made and how many were actually awarded is not clear. The serial number of known examples are in a range from 475396 (which is this one) to 475409. Clearly, they were all made in once batch and then awarded as Himmler saw fit. An interesting artifact of the Nazi Party's interaction with the German military!