The Revell kit is 1/32 scale and not promo based. It has a multi-piece body that needs a lot of fitting and fiddling to make it go together well. Detail is not great but it builds up into a pretty nice looking model considering the age. I believe that it's a Windsor and not a New Yorker and I'm sure that it's 4 door sedan and they never issued a convertible. Of course, an adventurous modeler could fix that.
The story on the Revell/AMT connection is foggy to me right now but I've seen a pretty authoritative account on another forum in the past. I suspect it might be that AMT, being a promo manufacturer, already had an exclusive deal to make models of Chryslers and Revell had to include AMT in on the action if they wanted to make a kit.
The modeler's rule of thumb: The worse it smells, the better it works!