Hi Stan
You could try keeping a saved search in ebay for "Pentax PZ-1" and hopefully someone will be trying to offload a broken one.
Either that or emailing a photo of the broken back of your camera to repair shops - although you may be a bit stuck for choice in NZ.
You could try a couple of places I know local to me in Perth:
Cal's cameras (no relation to me). Fixed my K10's mis-aligned sensor.
Cals Camera Repairs
Camera Electronic:
Repair Department - Camera Electronic Perth Western Australia
Best of luck
Cal