Breakaway holster desigend for the Beretta pistols 34 & 35.
The greenish finish is typical on the outside only.
The INK markings are placed inside upper flap : the crown 4UT 39 in an oval as well as the name of the GI (Kolski Jo) who brought back the holster.
This is a typical SAN MARCO Battalion HOLSTER with the general morphology evoking some holsters intended for the Walther PP or Sauer & Sohn 38. The greenish finish is suggestive of Italian origin military equipment.
This holster is detailed in the book about WW2 Military German Holsters on page 307.