My Dad had a 1966 Mercury "Cyclone" GT with a 390 Big Block V8 with chromed engine package and hurst 4-speed with red leather bucket seats and dual "ram-air" hood scoops....all included as stock. I go to alot of car shows and really have only seen 1 at a drag strip that was no longer original. I don't know how many of these they made but when his got totalled they chose not to replace it. He said he never saw another one when he was driving it and the one he bought was the only one on the lot. Was like $3500 back in '66.
It resembled the '66 Ford Fairlane GT but was much sportier.
I was born in '66 and it made a distinct, memorable impression on me! LOL.
His was a hardtop...here is a link to a convertible version that looks alot like it...his was red with a white racing stripe on the rocker panel:
http://www.cars-on-line.com/66merc13590.html
here is another rare one, last one down at bottom of webpage,
1969 Ford Talladega(only 745 were made):
http://www.musclecarplanet.com/History/Ford_69.htm