Once I've done as much stain removal and sanding as I can stand, is there anything I can put on circa 1961 oak boards that were shellacked or varnished with a light to medium stain that has yellowed over time? There's not a lot of the original finish left on some of the boards, the wood looks "thirsty" for lack of a better word.
What's safe to put on top of shellac/varnish original finish that will restore some color and lustre?