Northern Territory Prisons
Correction thanks from Don. This button looks like the logo for the Northern Territory Parks and Wildlife Commission, however, it is for Northern Territory Correctional Services, a title used since at least 1978.
The MAAS museum has a hat badge with the Australian Coat of Arms with the title “N.T.PRISONS” underneath, from the 1940s. https://collection.maas.museum/object/304341
Recent photos show prison staff wearing a khaki shirt with a silver button on each pocket. I am confused as to why the button has the eagle facing the opposite way to the one on the badge.
Generic Government Buttons
Not every government department gets its own uniform buttons. Perhaps some departments are too small, less funded or change their names too often? Some just have crowns, or crowns and cyphers;
Some, like South Australian Police (and other departments) have their State indicated;
Commonwealth departments, such as Customs have the Australian Coat of Arms; Don tells me this one was from the Commonwealth Police, however, I was sold one as being from Hobart’s Government House. More information is welcome!