Thanks Kaz, I have had a search around on Prime but can't seem to find anything. I cant help feeling that the cost of shipping for something that heavy would be high though.
I have seen others manufacturer alternators (Lucas etc) that claim to be for the NSX. Some look identical but they are only 70A and the pulley only has 3 ribs instead of 5.
Even if I swapped the pulley, would 70A work even as a temporary workaround.