Today in Postal History

This censored cover was sent from Rabaul, New Britain,
where it received a blue oval datestamp.
Rabaul, overseen by two volcanoes, is at the north end of New Britain.

Germany had annexed the northern area of New Guinea in 1884.
Germany included the islands of the Bismarck
Archipelago - New Britain and New Ireland - in this annexation.

Shortly after the outbreak of World War I,
Commonwealth Imperial Forces quickly occupied the area.
The whole area was placed under Australian administration in October, 1914.
The North West Pacific Islands included New Guinea,
the Bismarck Archipelago, the Admiralty group, and the westernmost
Solomon Islands of Bougainville and Buka, and Nauru.

This cover was franked with a single 1915 1d carmine
red King George V Australian stamp overprinted
N. W.
PACIFIC
ISLANDS
I believe this is Type II with the small upward white spur
to the right of the '1' at the bottom border of the left '1' tablet.
What do you think?
There isn't really enough of an image to be sure.

The cover, a commercial use to a stamp dealer, was
marked with a blue straight-line CENSORED handstamp.

The destination was Sydney, New South Wales.