Does anyone know where in New Zealand or Australia I can get a front grill for a 1200 coupe. I really want to get my hands on one reasonably soon. Willing to pay good money for one.

Have you tried the wreckers in the yellow pages. I don't know if you have a Datsun specialist wrecker over there, but if so, it would be a good start.

The 1200 ute was sold here in Australia up into the mid 80's [or later] & they seem to have used the coupe grille from about 74 & onwards, so perhaps you could ask your friendly Datsun / Nissan dealer.
Just ask for the grille, i'm sure they will know it is in the front.
Chris