I've watched the following clip about a dozen times now and can't stop being tickled or impressed by the brilliance of it. I found it over at the blog Retro Zombie, and hope the blog's author, Jeremy, won't mind me sharing it here. There's a clever dude on YouTube who is imagining what classic film trailers would have looked like had they been made in previous eras, and splicing together footage from older movies to recreate them, creating a "premake." This guy has imagined a 1965 version of Up! starring Spencer Tracy and Kirk Douglas, James Stewart as Forrest Gump (1949), and a 3D version of The Empire Strikes Back (1951.) But my favorite thus far is his rendition of Ghostbusters had it been made 30 years before the classic Bill Murray film, starring Bob Hope, Fred MacMurray and Dean Martin as the three paranormal scientists. Damn, the dude even got the Stay Puft Marshmallow Man in there! It works for me, and certainly seems heads and tails above the dreaded Ghostbusters 3 rumored to be in the works.
The song towards the end comes from a silly 1970s TV show called The Ghost Busters (starring some of the cast from F Troop) which had nothing to do with the 80s movie, but works so well here. You can see all of the premakes on this YouTube channel. Have fun!