I'm probably stating the obvious, but eBay is a good bet for a lot of this stuff. Maybe just list a bunch of it, and if it doesn't sell in the limited timeframe you have, then you get rid of it through some other means.

That is a fascinating collection of stuff! I hope you're able to find a home for it.

Edit: there are also lots of retro arcade enthusiast groups out there. I don't know where you live, but I'd search for groups like that near you. This seems like something that would be a treasure trove for them.