I only have 6 Russian M91-30's. One an ex sniper. I've taken them all apart for cleaning & shooting. I've just gotten one more, no shellac left on the stock any where. Looks like just oil finish. What surprised me was that the trigger housing is shimmed with a silver looking metal. The shims are perfectly fitted into the stock, the opening in it for the trigger is a perfect shape & bolt holes are perfect too. It's not a home made job. Does anyone know how often, why, or which armory did this shim work? Any help appreciated. Thanks.