The tool originated from the
Subsistence Officers in Bandung. (SE)
The Holster has the mark of the makers, the Construction Winkel (newly made in december 1923).
The gun indeed comes from the KOL series and should have the KOL logo on the receiver.
The marking on the brass sideplate puzzles me, it could be the marking of a newly formed (post 1945) mobile infantry group. Can't find the exact description in my docs.
The combination of items and the state of the gun could point to a refurbished/reissued 1945 - 1950 period gun. This would also explain the excellent condition, found on most 45-50 issued guns, since these barely left the armouries (no ammo

.
It might well be a 'set' made up by a collector, but I doubt that.