Thanks for the comments, Herb!
One further question. Why does the quality of the round number plate vary so? 454 seems to have an original Baldwin plate--complete with text wrapping the border. Were the K-27's delivered this way, and the plate survived all the rebuiliding? Many have a simple moulding around the edge with cast numbers, ala the T-12's and 346, I think. Some, like 223 just have a piece of steel cut in a circle with what appear to be painted numbers.
If I was the hogger for 223 and my loco got the round plate the same time as 346, I'd be pissed!
For that matter, how did the Grande come to use the rectangular plates? I cannot recall another road using this shape.