Closest thing we have to that in O gauge is the MTH RailKing scale MP15AC. I have one of these, and they did an excellent job on it, including the correct brakewheel, ladder, and the number boards above the cab, which was not common across all the roads.
Only thing to gripe about the MTH production model is that it has the earlier generation Blomberg trucks (with the Hyatt journal boxes), and not the more current Blomberg trucks that the catalog picture depicts. But at least they did put Bloomberg trucks on it to begin with.
SPSF, you did an excellent repaint job on that SW1500. And you're right; the good scarlet & gray, which is the longest-lasting paint scheme SP ever had, doesn't get its due credit in the O gauge world. Only thing you need left to do on that model is fab some number boards above the cab, or maybe see if you can get the boards from MTH that they use on the aforementioned MP15AC model.