M!ke, good question, because if the year means was 'born on date' we only have anecdotal information there--I'm not even sure if this on the build sheets. If this were a US car, the marketing cycle probably would have called it a '69'-- Counting on my fingers, 8ma602 is the 52nd car. But transitions on the goose--say, moving from 2 piece seats to single piece, single piece door panels to dual, 3 wire window motors instead of 4, AC in dash instead of under, etc) were clearly only reactions to supply chain (not model-year changes).
As a community, we only have a vague, anecdotal account of when cars were made. So for example, the distributor I have from car ~75 is dated July 1968, but so is the engine in 8ma1076. The bulkhead sticker on 8ma1046 was stamped September 1969 but because the distributor on 8ma1074 was December, 1969 I'd bet that stamp on 1046 was when the sticker was made (maybe months before the car). The red car here (8ma1120) lists July 1970 as its first registration date (and as a Euro car, maybe that plate in the rear fender was required to record this...) and the sales invoice (pickup by the customer) was September 1970.
Chassis out of order have been reported, I think 8ma998 was presented as "1971". Someone, somewhere, if not a few different people at least a few different names may have the real record...Lee