Re: M for Mike

I have been searching for my source amongst my hand written notes with no luck
IIRC this was a lettering scheme adopted by the Union Pacific in an attempt to keep track of which railroad the various cars and equipment belonged to. In this case the U stood for Union Pacific. A similar K meant the car belonged to the Kansas Pacific. The letter N was also mentioned but I do not recall for which railroad, perhaps Utah Northern.
I think it also mentioned that the letter was placed on a black diamond.
I would have more but years back my computer ate my homework
Am I allowed to post a photo of my model?