I always though the mottled figure was in the grain of the Baltic birch wood itself. That it was due to the stress the tree goes through during the severe wind and cold of the Russian winters. It makes it really dense like a typical GTA Liberal voter
I can't see Russians first putting pine tar on a stock then a shellac over it. It wouldn't serve a purpose. If they wanted extra grip on the finish the Russians would add ground vodka bottle glass to the shellac.