Not exactly. An actual Series II car would be a (model year) 1969-71. It's a pretty clear-cut delineation.
A (model year) 1968 is considered a Series 1.5 *although* some of the changes that constitute a Series 1.5 were introduced during the 1967 model year.
I think, then, that a 1967 car would be considered a Series I if it had *none* of the changes. However, if it had *any* of the changes, it would be considered a Series 1.5
(Isn't there a real E-type pro out there who can bail me out ? Help !)
Technically, and for the record, Jaguar considers all pre-Series II cars to simply be Series I. The "1.5" designation was never official.
Next, of course, came the V12 cars. All V12's (and only the V12's) were Series III.
Cheers,
Doug