I was able to purchase genuine parts for an R32 GTR from the Nissan parts guys on Albany Hwy...
Also parts I needed for my R33 and now R32 GTST aswell (RB25DETs)
I believe even if they don't have them in OZ, they can source and get them in from Japan.
I heard that you can actually buy like a brand new N1 block from nissan australia, but yeah I would just call them.