I had never heard of Hyborean Wars before Jodo mentioned it. I just read up on it. I could see something like thay working in a forum like this.
As for a game using the Ghostbusters rules, I've never seem that applied to anything other than Ghostbusters. After that game, West End Games retooled the system to make Star Wars RPG which in turn became the basis for the generic D6 System. After the D6 System rules came out, there was little need and probably little interest for adapting Ghostbusters to anything. You can maybe still download D6 Adventure, D6 Fantasy, and D6 Future for free. I can, however, see some value in doing exactly that. GB has a tongue-in-cheek tone to it which is almost unique.