My 1000 2 door sedan today was first registered in 1970 and its an early 1968 one that sat in a country nissan dealership before it was reduced in price to clear the showroom for the 1200s coming in. It has the short tail lights and early grill (the one after the aluminium one) and the owners apparantely had eyed it for 2 years before the day came in 1970.
Vicroads here think its a 1970 built car.
But it has no Australian compliance plate which makes it a 68 model.
I think the last one rolled of the line in late 69 and I had a sept 69 one with 23,000 miles my mate bought from me with original japanese shipping papers and has the late long type lights (2 door sedan).
There could have been registered in 1970 but maybe some did get built or assembled in early 1970 to get rid of stock laying round.