hypercapitalism
AUSTRALIA UNDERGOES HYPERCAPITALIST DETERRITORIALIZATION
Are they worshiping fucking Gnon yet?
But really: Australia doesn't really come off as a country that could populate itself that quickly considering that... well... you know, 90% of the country looks like this:
And it's agricultural industry only really relies on these:
And other than that it has coal and opals which aren't exactly a hardcore commodity that'll make it the next Saudi Arabia seeing as how it hasn't yet either. You're also talking about an insane rate of immigration to boost a population of roughly 10 million in 1960 to overcome Indonesia's 80+ million in order to correct a head count imbalance. Seventy million people in forty years is going to destroy a country's ecology, which'll make those moo moos effectively economically unsustainable. It'll be a country forced to import more food than it can produce and even more vulnerable to war, only meaning the government will need to shell out more in defense to protect the incredibly valuable cargo vessels so the entire country doesn't fall into a state of instant siege the moment a warship leaves Sydney.
Australia is, realistically, a country that relies on London. And it may be defacto independent of Great Britain from distance, but when you get down to it it can't actually survive on its own if there are active threats in the area. If it were to be legally independent of England then it's position may end up being like that of Switzerland, keeping a strict neutrality in anything as a matter of existence. Otherwise a resurgent Japan will swallow it, emus or not.
What you're asking for is impossible, and I will need to hit the abort button before you even start.