The actual year the bike was first registered as NEW bears no significance to the model.
For example, my current bike is a UK/Euro Spec Z1300 and by frame and engine number was manufactured in early 1979, but not first registered as new in the Uk until March 1981.
By model YEAR that would make it a late A2 or even an early A3...............when it is actually an A1.
The reason for this is many Kawasaki Dealers had stock of the Z1300 in their showrooms for very long periods and could not sell them as they were very, very over-priced in the UK compared to other countries so the old stock bikes ran over into next years models in many cases before being sold.
Kawasaki UK also had large stocks of Z1300's they could not "force" onto dealerships as they already had their own unsold old stock !!
This was quite common with many Japanese bikes back then.
The A1 and A2 UK/Euro Spec models were almost identical, including the colour and most other specs.
Pete F
UK