[Don M]

The pistol is a 1920 dated DWM. It is one of the ones in the perplexing "n" suffix range.

As Dwight says, the unit markings are from the Schutzpolizei of Berlin. Although the photo doesn't fully support it, I am positive that the original marking, in accordance with the 1922 instructions, is S.B.W.I.R.268. which was from the Charlottenburg Inspectorate (see HWIS, Chapter 5). In 1932, this marking was partially canceled and replaced with S.B.5418. in accordance with new marking instructions.