Some missed factoids here. Aykroyd wanted John Candy to play Louis, Rick Moranis' character, and Eddie Murphy to play Winston, Ernie Hudson's character. He also wanted Paul Ruebens to play Gozer in full Pee-Wee Herman get-up. I think Sigourney Weaver's role was originally meant for someone else, too. It's escaping me at the moment. Winston originally entered the script earlier and was the one who got slimed. Sigourney accidentally flashes the camera when she's struggling on the armchair. A deleted scene involved Murray and Aykroyd playing other characters (homeless men in a park who Moranis runs by when being chased by the Terror Dog.) The original concept of Ghostbusters 2 was called "The Last of the Ghostbusters" and was to involve the Ghostbusters in hell, which Aykroyd later repurposed for the unproduced third movie script.