Well, here's what I can tell you off the bat:
-When a person is deleted, the unique modifier for their posts is deleted, changing it to guest. There is no way to restore it back to their modifier. I'm not sure if his modifier was reset to guest, and have no (known) way of checking, but I would assume, since the account was deleted, that it was. The only recovery for that is to restore the posts (would be nice if we can just restore the posts and his account, and let those tables overwrite, but none of the others. Depending on the SMF's table layout, this may not be possible. Not sure...
-I definately would not want to roll back the forum either.
-I would love to see what I can do with the tables, but I haven't got access to the MySQL stuff on the server. My adminship is just for the board, and not for glest.org itself, so I can't do anything there. It's up to the glest team if they can do anything about that. :'(
-I will try and experiment with my backup by importing it into a dummy copy of the board offline, deleting an account, and seeing if I can recover it. If successful, then the glest team can apply it to the Glest board.
-Post count cannot be permanently faked, since it depends on the posts, and can be recalculated, its not a static number.
-For now, I've made Kukac's new account a moderator.
Still open to ideas. I checked the SMF forums and back was the only really mentioned way. For the most part, there wasn't many helpful replies there.