Hi Karhu and welcome.
Here is a classic Tikkakoski barrel on a finn luger
Finn Lugers may have well started life with wood grips but through the course of use many got plastic replacement grips. They were better on the field because the wooden material would swell in the more moisturized environment. The history of Finn small arms is one of constant fixing/upgrading/re-arsenaled and constant reissue and recycling to the army. Most do NOT have much in the way of matching small parts but most DO have replacement Tikkakoski barrels that are very well thought of and most are very accurate.