Spook Central has up two very interesting pdf's. One is of Ghostbusters: The Supernatural Spectacular Novel, written by Richard Mueller. It is a Novel based on the first film that is expanded on. Includes deleted ideas for the movie. Second is a pdf of the Ghostbusters film script written by Dan Aykroyd & Harold Ramis for August 5, 1983. Winston is in the Hotel in this version! Anyways, to go to Paul's blog which links to the pdf's.
http://www.theraffon.net/~spookcentral/scblog/index.php/2011/09/25/ghostbusters-pdf-ebook-project

Paul Rudoff was the manager of both projects and provided location for finished efforts. Patrick O'Riley scanned and provided the script. I cleaned both pdf's and scanned and provided the novel.