I like to build secondary Santa Fe passenger trains like the Grand Canyon or the Fast Mail. I would appreciate some expertise on NYC head-end cars which ran in Santa Fe trains. During the postwar era, there were multiple daily cars of storage mail interchanged from New York Central to Santa Fe at Chicago. The only ones I can remember seeing in California were heavyweight baggage cars painted green or grey. I have also seen photos of what appears to be converted WW2 troop sleepers from NYC in Santa Fe mail trains.
Did NYC ever paint heavyweight baggage cars in the 2-tone grey? If so, were there many, or perhaps just a few for particular trains? When did NYC start painting heavyweight cars solid grey and when were the last green ones repainted grey?
Thanks in advance for any help on this.