Try control f and search for varnish, I think. Henry can probably answer this off the top of his head but we have talked about it before. There are a series of tests you need to do to determine if they covered the stain with varnish, shellac, poly, or something else. Once you use the right chemical to remove the finish, then you can deal with the stain. Maybe all you need to do is refinish it if the stain is still ok.