Re: A foto of 456 on Facebook

Ron, from what I've heard the engines used to be 'assigned' to their specific engineer and fireman and they were responsible for the condition and the maintenance of the locomotive while in service. It was supposedly Burnham Shop's policy that if a locomotive came in for major overhaul and it had been maintained to a certain level of care that the locomotive would retain or receive a round number plate. If the loco was in poor condition or obviously neglected for some reason the loco would retain or receive a rectangular number board. This 'award' showed the railroad world that the crew in question was either top-notch or sub-par and was intended to inspire more crewmen to receive the coveted round plate through additional effort at maintenance.

When the practice of assigning locos to crews was replaced with random, first-in, first-out assignments this practice was discontinued and at that point in time the locos henceforth retained whatever plate was assigned at the time of the change, with the rectangular plate becoming the railroad 'standard'.

Info on this is from Lew Lathrop's Little Engines and Big Men, long out of print and frequently questioned.