Can't remove bathtub stains

Hey All, My bathtub has been unusable for some time now due to some stains that I can't remove. I'm not sure of the exact material the tub made out of but it's a standard plastic, slick like surface that you see in most tubs. It also contains air jets that didn't work when we moved in, if that has any relevance. The stain is a mixture of two things - A non-toxic chemical varnish stripper (the exact brand and chemical escapes me) and polyurethane varnish to finish a wood floor. A waste bucket was accidentally knocked over and not discovered until the following day. (Don't ask, ugh.) Below are some images of the bathtub: http://i.imgur.com/URWqAVl.jpg http://i.imgur.com/p4IieFX.jpg