I was just up on eBy and seen this:
http://www.ebay.com/itm/Vintage-Apple-Computer-PROTOTYPE-IIgs-II-ROM3-MUST-SEE-/280872108588?pt=LH_DefaultDomain_0&hash=item416548422c
The auction title lists it as a prototype.
I can see differences in the pictures provided, but not that many and not anything drastic.
Any opinions?
Steven 
I probably wouldn't quite call it a proto; it looks like a unit used in Apple's internal SQA lab. Over the years I've seen a fair number of ROM3 boards of different PCB colour and a few that had EPROM instead of masked ROMs.
Agreed on the internal lab use. Still, I bet some flunky will bid on it soon enough. Bwaaaahhhahahahahaaa
Heres a for sure it was owned by Apple and it was Before its public release. Now is it a prototype there's no way to know it is possible it wouldn't be that different since the IIgs was already out the only prototype part really is the main word they just took the rest off the self from he rom 1 series. Overall I'd say 50/50, eitherway a rare find and comparing to other prototype prices lately it's surprisingly "fair" though I wouldn't buy it personally