Fozzie, whereabouts in Australia are you? I'm willing to bet someone locally has a machine, although I don't know of anyone specific there may be some leads to be had by contacting local puppeteers. The other thought I had was finding a hacker space:
http://hackerspaces.org/wiki/AustraliaThey seem to be mostly focused on computerised gadgets, but it could be that one or two of them have machines for vacuum forming. The Melbourne one states on their site: "Whether it be electronics, metalwork, 3D printing, woodwork, laser cutting software, rocketry, machining, we most likely have a member who has experience in a particular field. "