I am a prop collector,and BIG fan of the Ghostbusters. I have been trying to find out for years what happened to everything dealing with the show, and also trying to purchase anything dealing with it to preserve it's history for future Ghostbuster fans to enjoy.
I heard from someone years ago who used to work there, yes many of the props and sets that were destroyed, BUt many things were put in storage behind Universal Studios someplace. But, I also heard that Sony, who now owns the rights to Ghostbusters, owns whats left of the attraction.
I believe Sony owns the props and this why. A few years ago, I was at Planet Hollywood in New York, and they had a big Ghostbusters display. It featured all four Ghostbusters uniforms from the second film, a ghost trap and proton packs. Two of the four proton packs WERE the ones from the Universal Studios show.
I know this is true because there was differences in the ones from the movies and the ones from the Universal show:
The show packs have two extra orange lights on the back pack, the movie ones don't have these.
The frame the pack is attached to is different. The movie ones were military Alice Packs i think it was called, while the show ones were regular hiking back pack frames. You could see the metal poles from the hiking back pack sticking up above both sides of the pack.
The packs also changed as the show went on. The original ones used in the BE A GHOSTBUSTER video louis Tully shows the audience and when the show first opened were made by a talented prop maker in California. These were very detailed and close to the movie versions. Later, it cost to much to buy now ones when they broke, so they hired another company to make them. These were made with much less detail, looked different from the originals (especially the proton guns), and made so if one got broke or damaged, it could be replaced very easily with very little cost. They were hollow plastic shells, with lights.
I know Landmark Entertainment designed the show, but I can't remember who made the packs. I'll get back to you on this.
So, I believe that some place out there, the props do still exist gathering dust and rotting away in some storage facility, or some dump pile (which I hope isn't true). But, with the anniversary of Ghostbusters coming up, and the talk of a Ghostbusters 3 in the works (we hope), hopefully the Ghostbusters will be busting ghosts at Universal Studios again, or another theme pack.