Frank Libuse of Atwater Models, Milwaukee , WI modeled the EMD F3 for a die-cast O scale Model in 1948.
1949 the F3's are brought to market by GMC ( General Model Corporation).
End of 1950 GMC declares bankcrupty.
End of 1951 GMC assets are sold to All Nation Hobby Shop .
Mid 1950's All Nation again offers the F3's which would be a main motive power leader for decades .
Here are a pair of Atwater marked F units C&NW running with outside 3rd rail, Burlington running 2 rail.
Please see link for video action.
Why is the Burlington B unit backwards ??? Because it stays on the track better than the other way