Sorry for the resurrection, but I went and read this for various reasons, and actually looked closer, and realized.
The holster is most likely not Finnish, but Swedish. The text of the stamp is what makes me say that. The text is "Kontrollerat o Godkänt", or "Controlled and Approved", o short for "och", a common contraction back in the day. Another interesting thing, at the top is KKV, for Kungliga Krigsmaterielverket, the "Royal Warmateriel Authority", the procurement agency of the Swedish military up until 1954. Interestingly, it also did not exist until 1943, so if it is part and parcel with some part of the hybrid pieces, that gives some timeline parameters. This would suggest either not actually civilian, or at least surplused out.

...!
Stoke Mandeville, Esq & The
Victorian Ballsmiths
"Nobody Want Verdigris-
Covered Balls!"