He joined the forum over this end of the pond, but hasn't been to a meet as yet.
Unfortunately you've just missed out on a group buy of goods from the US. One of the guys brings Z bits in on a regular basis, saves heaps on shipping, won't help in the interim though.
http://www.300zx.co.nz/phpBB2/viewtopic.php?t=6376
Have the Nissan techs put it on the fault reader??? Just to double check.
Financial club members of the Zclub in NZ, get good discounts with one of the Nissan dealers.
It may be worth giving Dave @ Z parts in Manukau a call 276-7376 or Soichi at St Hitech in Mt Wellington. Dodson Motorsport have worked with a number of 350's, not to mention many other monsters - http://www.dodson.co.nz (as their motorsport site seems to be down) - ask for Glenn.
We really have no one here who is an absolute expert in all things 350, unfortunately.