If this helps, I once heavily linseed oiled a stock, then changed my mind and later ,amber shellaced it and it holds on good to this day, that was two years ago..I think shellac will go on anything, its worth a try ,if it doesnt go well it cleans off easy with denatured alchohol...I think I read that shellac will seal in anything, and is used in "Blocking" type primers that seal in smoke damage and stains that bleed thru other primers and paints, check wikipedia about that. pills and candy are also "shellaced" . The Russian finish is Amber Shellac, and the redder finish is the same with aniline dye added. Shellac is the "old world" standard made from bug secretions..