Talking to the guy that repaired mine, he said that rebuilding the rad for a gen1 fazer would not be a problem, including making new mounting points. He said that the main section was pretty standard size so he would cut it out and replace it with one from a car, keeping just the original side pieces where all the hoses connect. He didn't seem to think it would cost much either. Since you have effecivly have a spare rad, it might be worth finding your local specialist and seeing what they can do with it.
(The gen2 has a curved face which would make this much more tricky. Not impossible, but not cheap)