I bought a Yugoslavian SKS in excellent condition, metal dark and shiny, bore clean and bright, and a almost perfect blond stock. For protection, I put a coat of Boiled Linseed Oil on it and it turned the wood into a sticky texture that wouldn't come off with alcohol. Before I take mineral spirits to it, I thought I would seek some help. Could this stock have been shellaced or otherwise coated with a protective shield I shouldn't mess with? Like I said this one's a beauty and I'd hate to mess it up. Thank You.