No expert here, I just spend an unhealthy amount of time on youtube watching old American car relics forced back to life. So ignore what I say, I'm probably wrong!
Anyhow, not 100% sure, but I think there is a difference in width, the Coupe de Ville being approx one inch or so wider. As I understand it, there is a slight issue with swapping some chrome / trim between the two, though it can be made to work.
Other than that, it is all exterior chrome trim, some slight mechanical differences (standard fit / options mostly), and interior trim, which separate the two models.
I await to be corrected, and I will be...
