Actually Andrew, they stopped production of the Eldorado as a vert in the 1976 model year.
It was touted by GM as being the "Last American Convertible" and everybody went nut's buying them and putting them away with no miles on them. Dealers were marking sticker prices up accordingly.
I remember there was a big stink raised by the owners of all those "Final" Convertibles when GM started selling Convertible Caddies again. I think there was even a class action lawsuit.
One of the things I liked about the later model Eldorados (like Terry's) is the fact that they don't have "fender skirts".
My favorite Eldorados are the 1967 models.
I bet Terry's car is a rare site indeed where he lives. I'd like to see a photo of what the right hand drive dashboard looks like.