Not 'adopted', John, born here, lived overseas, only ever an Australian citizen.
As to Flynn's accent, you might be surprised. I was, when listening to a 1940 newsreel group of 10 Squadron RAAF Sunderland crew at how 'British' they sounded; very different to our expectation. No idea what a 1930s Tasmanian accent might be like.
For instance here's Jacqueline Cochran talking in about 1942 - very different to a modern American accent, Florida or elsewhere.
http://www.britishpathe.com/video/girl- ... rom-u-s-a/Neat little film, by the way.
Despite combing film records in detail, I can't find Flynn playing a Tasmanian, dammit.
Um, can we stop trying to sound piratical now?