From what I was told by my cousin the rifle came from his girlfriends ex husbands grandfather.
If what I've read off of 7.62x54net is right, the stock is a reworked Russian stock (due to the off center cross bolt) spliced by the fins. The parts are not matching and have a mix of pre and post 1928 arsenal marking. The rear sight base has a D stamped on it. Is this a D mark indicating the rifle is made for the Fin D cartridge?
Also shouldn't this rifle have had sling hangers fitted in the sling slots?
Would this rifle have been issued by the Fins with a M91 bayonet?
The stock is a rework with a spliced forepart. This was usual practice for the Finns to give a bit more stability to a stock by using arctic birch, a wood impervious to weather and temperature changes.
Be careful if you refinish a Finnish stock: depending on the district, they can have a different way of refinishing; some used pine tar mixed with beeswax and turpentine, some plain shellack and some (the LapLand ones) pine tar with melted reindeer tallow. And some were issued with no finish whatsoever.
Yours looks like pine tar has been used. The stuff they use under wooden skis can do fine when mixed with a bit of beeswax and turp or simply applied raw.
Some stocks weren't equipped with wire hangers because there wasn't time to put some on.
Finns were very practical people and the parts mix-and-match was common practice. The Mosin-Nagant original design asked for parts interchangeability to a high degree and the Finns tested the envelope to the limit.
The D stamping on the sight ramp usually tells the ramp was modified for the D cartridge trajectory and another step ground at the rear to allow a 150 meter setting.
The fact that your Tikka-made barrel was counterbored tells the urgency of these times; probably a field armorer's job. Obviously, yours has "seen the Elephant".
The Finns used the Mosin bayonets if they had them but the Puukko knives were their preferred mean of hand to hand fighting.
PP.