I found this photo of an Aberdeen & Rockfish GP18 on Railpictures.net:
http://www.railpictures.net/viewphoto.php?id=119219
Now, the nose, cab, and radiator screens all identify this as a GP18, but the fans do not! It has four 36" radiator fans, instead of the two 48" fnas that a GP18 typically has. Does anyone know what the story is on this one?
They bought it brand new, but traded F3A 200 in on it. Perhaps the F3A fans were used on 300 to lower costs.