Have you tried generating a PDF using PDFLib.com or just generating a HTML file and then pushing it through a PS/PDF convertor such as HTML2PS? Don't forget you could use CSS to set the media layout for each page when displaying it.
The really difficult bit is making sure that not only has the user removed any specific print margins, footers and hearders, but that the paper is aligned in the printer correctly and the right way round... Sometimes it is easier to ignore the pre-printed paper and print the entire form from scratch to your (tweaked) specifications.