The 912 expands the number range because both Porsche and Karmann were making bodies and each have a unique serial number.
Starting in calendar year 1967 is the "Targa" body style, with its own numbering.
There are further model breakdown by 911 and 911S but there are no records for separating the two in 1966/67 as both used the common sequence of numbers. Bruce Anderson was able to talk with the factory and has probably the most accurate numbers for 911S from this period.
Bob
