I've been watching a lot of LGR, which focused on retro computing. After some wandering the tubes, I found this here link.
It creates a 1GB disk image wherever you tell it, and then you can run a fully-functional instance of MacOS 9 in a window on, well, Windows. You can transfer files back and forth between it and your main OS, and as far as I can tell it's fully functional. Only limitation that I've found so far is that it can't go about 1024 x 768 or go full-screen.