RE: 1959 or 1960?

Listers,

I found out my Sprite was built on 7 october 1959, and shipped to the US on
9 October 1959... and the car was first registered by the DMV in California
in 1959... So it's a 1959, right?

My VARA log book for the same car says it's a 1960. Is this a mistake?

I also found out my car was built with "heater, less sliding sidescreens".
Does not seem to make much sense- if I wanted the heater, I would certainly
want the screens to keep the heat in...right?..

Jacques Le Clainche