Trying to decipher the mystery of what is being communicated inside this 1926-1927 holster (other than "Sauer 7,65" on the 2nd line which is very clear). Here is the sense I make of the handwriting:

1st line: "No 123 des _ _ _ Verz."

3rd line: "P.A.W. Reuter Ku _ _ _"

4th line: "Dienstgebrauch _ _ _"

As for the dienstseigel (assumed meaning of the ink stamp) I am clueless but have pasted a few Freistaat Preussen examples in the picture below: