I have an antique Streamline travel trailer. The previous owners covered the lovely curved front corner windows with a laminate like formica and glued it to the inside of the front corner windows with what appears to be contact cement. It's turned ugly brown through the years of sun exposure and looks awfu. The problem is that these curved corner windows are some form of plastic so removing with laquer thinner or other strong solvent will ruin the plastic. Any ideas will be sincerely appreciated. Thanks.