Twenty plus years after the fact -- I had one of the Precision Scale gons and came up with a photo of it somewhere painted CNJ. There was a Herald King decal set suitable (suitable enough ? I no longer remember) but with all the discussions of 65' gons a few months back I realized I couldn't find whatever it was that prompted me to choose that prototype. Well, here it is, so thank you.
Incidentally, it turns out that the home-built MP 5100-5149 65' gons of 1948 are substantially the same car.