I recently acquired this Sauer 1913 pistol from a local hock shop.It's marked on the grip strap S.(chutzpolizei) B.(erlin) 2417. and the mag is marked with the pistol's serial #. There appear to be earlier, erased unit markings under the existing marks. The holster is incorrect for the Sauer as it's for an Astra 300. Here are some pics.