What could have been... painted in NS black due to a cancelled Tier-4 order, EMDX 7233 is lettered "Progress Rail - A Caterpillar Company" and currently working for KCS.
Louisville & Nashville GP38-2 #4121 at the Tilford Yard Service Center. #4121 was built March 1973 on order #72635. Unit later became Seaboard System #4121, then re# CSX 2628