It would be nice to see old network started up again. Anyone knows how to do that?
So logically just someone with an old Copy of the Chain should start his Full-Node again and start hasing on it, normally it should be that longest chain if not waited to long

good question, it was restarted on Dec 6 since noone had the original chain. Perhaps there will now be two incompatible chains, the original and the new one, as the blocksize wars predicted.