A very important find indeed, Owen, and indeed I can add to it.
In her autobiography Mandy (London, Michael Joseph, 1980.), Mandy Rice-Davies mentions that after her notoriety broke, she toured Spain, Australia, Hong Kong and Singapore but was banned from entering New Zealand as a result of a complaint from the Girl Guides.
So it doesn't take a massive leap of imagination to realise that Mandy Rice-Davies and The Maid of Australia are in fact one and the same person. Q.E.D.
All the evidence now points in the same direction, especially - as Owen emphasises - that the Antipodean Maiden was distinctly trouserless.