Cracked Campy Record 8 speed rear derailleur
 

I noticed today that my rear derailleur has a crack right at the top bolt that connects it to the frame. This is more than a hairline crack. I've never wrecked the bike. Has anyone come across this in the past? Wondering if I should search out a used 8 speed replacement of if a newer derailleur would work. Any help would be appreciated.