Ed: Thank you. Yes, that would explain the extra fan, and the space behind the radiators. NJT had some GP40PHs, with the steam generator/HEP space, but they had conventional radiators. Either way, kind of a letdown for a passenger unit to end up switching coal cars.
Sirenwerks: That was my first thought, but the GP40X doesn't have the extra space. I also thought that, maybe, they just grafted a new set of radiators onto a GP40, but then it should only have three fans.
Believe it or not, another picture of this same loco, on the same website, identifies it as an SD45-2, which it most certainly is NOT!