"I have a '60 P210(based on the production numbers) that is titled as a '61, and a '66 P120 titled as a '67. It was common in the sixies to title the year of the car when it was sold. Who wants to buy a new '66 in 1967? The dealers can't get away with it now."

Yes, that was common in the 1960s. In North America new cars were introduced in the fall of the previous year while imports came out a lot later or early in the new year. Nobody wanted to buy "last year's" car, so import dealers titled their cars a year ahead to compete with the domestics. I bought a new 1965 MGB and only later discovered from the features that it was really a 1964.
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1992 745 approaching 500k km