Oceania Section Of The Madagascar Upu Archive

You may be familiar with the stamps from the Madagascar UPU archive. I have the New Zealand Postage Dues here:



I know George Alevizos sold non British Commonwealth sections of the archive in 1990, Argyll Etkin had some of the British Commonwealth material a couple of years earlier (?), but not the Australian or New Zealand material.

Can anyone help me identify how the Australian and New Zealand material found its way to the market and when?

Thanks,

John