My 1911 home's main bath has plaster walls with original tile scoring on the lower half. The plaster, while it has a couple cracked places seems sound and well attached yet. It has been painted and was even papered (upper). I have stripped paper and nearly all the paint down to what I think is the first layer or 2 which seems to me to be a yellowed layer of white --maybe milk-based? Or maybe it's the aged surface of the plaster--I can't tell.Having trouble stripping a few areas and am worried about how to prepare rest to be painted. I've thought about covering the bottom with beadboard, but wonder if the plaster will hold. Can't afford to remove and start over. I'm stuck for what do do next. I have limited funds to spend, but HAVE to finish it somehow! HELP, please?!!I am open to suggestions!