GRS 640/663..The mysterious U30C

Anybody have any history on Guilford (B&M marked) U30C # 663 / 640. Not too much info on the web about it. About all I know is it was Ex-Con Ed and no longer in service, and as far as I can tell 640 and 663 were the same unit.

Please don’t tell me that they painted 640 on one side and 663 on the other. What happened to the other 663/640?[}:)][:-^]

These days you never know…but from what I gather it was Con-Ed 12 then became GRS 640 and was then renumbered 663. It was the only U30C that Guilford had. They had the U33Cs that they got from D&H. This was one of a kind and didn’t last real long from what I gather. I’ve seen a few pics of it. I was just trying to get a little background on it. Like why they’d buy just one. I know they paired down to EMD only to save $$ on maint and parts and (whispering)…because EMDs seem to be able to go for ever.