With reference to Queen Victoria who died on the 21st day of January 1900, no new Letters Patent have been issued until August 1984, which is 4 Monarchs later.
(1) First, it does not remove all existing British law used in Australia. It only refers to new British law. Any Australian lawyer can testify that the Commonwealth and State Statute books are pregnant with British law, the most obvious being the Commonwealth of Australia Constitution Act 1900 (UK).
(2) Second, the termination of British law in Australia that is supposed to occur with this Act, when challenged, will be determined in a court which is dependent for it's existence on the very same British law!
(3) Thirdly, Australia continues to have a monarch who derives her power from the British Parliament, and she remains the Executive Head of Government of the six Australian States. So to exercise her power in those States, her power must be seen as an extension of power of the UK Parliament.
(4) Lastly, at the very time that the Australia Acts came into law in Australia to prevent the UK Government from interfering in Australian matters (see also Sue v Hill HCA 30 of 1999), the Letters Patent relating to the Governors of South Australia, Tasmania, Victoria, Queensland and Western Australia was signed off by none other than Sir Anthony Derek Maxwell Oulton, KCB, QC, MA, Ph.D., Permanent Secretary, Lord Chancellors Office, UK Parliament!
“We the Australian people commit ourselves to this Constitution”(The proposition was rejected in every State and Territory of Australia on a national basis of 60.66% to 39.34%. see end note.)