Folks,
Re. Au and NZ, acquaint yourselves with the Trans Tasman Mutual Recognition Treaty ---- CASA simply hates it, it is that good!!
In years gone by, several OS carriers did have domestic rights, the examples I remember are Air India between Perth and Sydney, and BOAC/BA between both Perth and Darwin and Sydney.
Not all that long ago, there were several such cases dormant, they haven't, to my knowledge, been used for years --- if any still exist.
Tootle pip!!