Ron, It can't be all Shellac. Denatured alcohol was my first try and that wasn't working. My best guess is someone did a re-coat at some point with something. The Citrustrip is working well, but I am taking my time partly because I want to be careful and partly because I am short on play time these days. I am wondering if they could have used one of those stain and sealers in one? Even after using Glenn's recipe for cleaning I wasn't seeing the normal result I am used to getting.