The 4-8-4 "Northern Class" wheel arrangement was one of the most popular among the major railroads as it proved to be very efficient. But, of course, every railroad had its own idea about what was the ideal wheel arrangement and cosmetic look of the locomotive. The following locos feature some adaptations to the basic 4-8-4 mechanism to make the models look cosmetically more like the individual railroads version of the 4-8-4.
All models except the Pennsy version include a coal bunker tender, new smoke box door on the front of the boiler that features a center-mounted headlight and a bell mounted at the top of the smoke box. The Pennsy version has a coal bunker tender, new smoke box door on the front of the boiler that features a top-mounted headlight and a PRR Keystone logo in the middle of the smoke box door.