Since Ford destroyed the data to make room for the 67-68 years, most of the hard data is lost. You can get a general idea (there are accurate numbers for body styles, engines and some options, just not how many were put with other options) but not narrow it down. For example, you can find out how many fastbacks were produced in 1966, and what percentage of Mustangs in general had a particular paint color and what percentage had a particular engine. But putting them together is a guess at best. Were more fastbacks than coupes K codes? Were more convertibles red or black? It sure seems that way today. There is a book based on surveys called "Mustang by the Numbers" that looks at percentages of car options based on responses, but not much else except anecdotal evidence.
Daniel
