I've spent many hours doing similar things to this--my most recent was building Virtualbox VM's of the more interesting abandoned and ancient OSs from WinWorldPC. So far I've got working versions of OpenSTEP, BeOS, SyllableOS, Plan9, Solaris, ReactOS, Memphis/Neptune/Chicago, OS/2 Warp and ECommStation, and another dozen or so. When I say working, I mean bootable with a network connection of some type, though mine are usually a little higher up the stack than raw UDP.

Thanks for a great read, love ideas like this if for nothing else but to keep one's nerdiness and thirst for obscure trivia alive.