What United States railroads used Fairbanks
Morse Trainmasters?
To list a few, the Reading, the Jersey Central, the Pennsylvania, and the Southern Pacific. Here is a good site with some prototype info:
http://nscalesupply.com/ATL/ATL-LocomotiveFMTrainMaster.html
Hope this helps.
The Lackawanna, Erie-Lackawanna, Wabash and Virginian, had them also.