Wow. Can you tell if the core is shot or just leaky? Does it look all corroded up?
Maybe contact Sims Radiator here and see what they'd charge to do it or see if they can get you a brass/copper radiator for less money. I bought a new brass radiator for a '66 Mustang two years ago from them for $200. A recore job on the original was going to be $400.
Sims Radiator 770-939-8020
www.simsradiator.comI'd buy the new copper/brass radiator from somewhere if there's no hope in fixing the one you have.