I found this phone last week on ebay. Nobody had bid on it, so I contacted the seller after the auction and worked out an arrangement to but it from her. I t is here now, and I am trying to learn more about it. The color does not really look like ivory, but more like a light beige. I do not believe that it is discolored ivory because the inside of the shell is about the same color as the outside. The paint job appears to be from the factory because there are no signs of it having ever been painted a different color (there are a number of large chips and no other paint visible), and the "H 1" on the inside of the shell is clearly visible and not painted over. The base, ringer, coil, dial, receiver and transmitter are dated in 1940. The cords are from 1955. The line cord is vinyl and looks like it was installed by an amateur because of the knot inside the shell white adhesive tape wrapped around both ends. It is about the same color as the phone. The handset cord is coiled cloth. The handset is brown solid bakelite and has no groove. The plungers, dial (5H), and finger wheel are black. I expect to replace the dial with one which has white sides, and I would like to find a clear finger wheel and the hardware for attaching it.
The phone likely spent its life in Wellesley, MA (in a very upscale neighborhood).
Picture from the ebay listing:

The handset on the right edge is an ivory painted F1 from a WE Imperial (lamp) for color comparison, though the color appear more different in person than they seem in the picture:




Larry