Okay, sounds like you have no better idea than I do. I guess I'll have to do some more research. I had found a document on the city website listing all the street names and alternates a month ago when I was trying to research the situation in the West 60s. But there was no clarity in it about how official they are (does the city use them when referring to street work? does the post office honor them so that they be used in addresses?  etc.).

I'd never heard of Odessa Stewart  Street until I saw your edit. I had been aware of the Norman Rockwell naming for some time.