My '71 has a build date of 5/71. I bought the car new on 1/27/72. The Calif DMV title shows the "date sold" AND the "year model". The "year model" shown on my title is (was) '72.
A few decades later (I'm slow), I called the DMV and questioned the year model. I was told that Calif was only interested in the "date sold", and that the "year model" "defaulted" to the year that the car was sold.

I was also informed that they (the DMV) had recently (mid 90's ?) made a change, so that new titles now showed the actual "model year". The old titles remained unchanged. I inquired about changing my title, and was given instructions on how to make the change. So, in 2009 (I told you I was slow

While this title change had no real impact on the car's value, I made the change because a) the title now reflects the correct "model year", and b) if Calif ever changed the smog laws to include '71 cars....
John
And to further confuse things, here are the dates from my Marti Report.