I am personally not aware of any Australian gairago. Being Dutch I looked at imported words before due to rangaku in the 17th century, followed by importing some Portuguese and later massive English import of words. And nowadays the eyes and ears are very focused on US English to the point where speaking with an Australian or UK English accent actually makes it more difficult for Japanese to understand you.
I guess the only Australian import words will be limited to the standard kangaroo, koala, dingo, and so on. But I am not sure if we can call that real Australian English (due to these words coming from Guugu Yimithirr, Dharuk)?