Haven't looked for a few years -but don't believe there's been any rule changes.
Pre 89 should be automatically eligible.... just meet appropriate ADRs (Australian Design Rules ) for the year it was built to be registered.
Freight charges are highly variable - and from memory were cheaper from UK than from NZ due to higher volume of shipping.
Anyway - this following topic lists all I went throujgh (and some useful links) when I imported from NZ. (principal the same)
http://www.ausmini.com/forums/viewtopic.php?t=25795&highlight=import+elf