Ok, it won't often help for the IMCDb 
But this enthusiast's website gives a lot of details that can help identify the Blackhawk models and derivatives (D'Italia, Bearcat, Diplomatica...). It also has some pages about the 1965 Mercer-Cobra, the 1965 Exner-Bugatti and the 1966 Duesenberg.
http://www.madle.org/estutz.htm
But this enthusiast's website gives a lot of details that can help identify the Blackhawk models and derivatives (D'Italia, Bearcat, Diplomatica...). It also has some pages about the 1965 Mercer-Cobra, the 1965 Exner-Bugatti and the 1966 Duesenberg.
http://www.madle.org/estutz.htm