Hello saber, I currently know a way to repair the old server to work with the version 1.3 update.
Upon telling you this I just ask that you may make me a moderator, you do not need to it is just a request. No matter if you make me a mod or not here is how to fix the server.
You must still have the files for the old server!!!
Access your %appdata% folder on you computer, then in .minecraft go to saves
copy and paste the world file from the old server into your saves. Run minecraft and play single player, select your old server's world and let it convert the world to be capable with the 1.3 update then go back to your saves folder and copy the new configured old server and paste it in the current server. Let it replace the new world and next time you start up the server the old world should work! I hope this works for you.
I would like to become a mod if that is ok? Just a side request, no need to allow me to become one.