I'm pretty sure (read that as certain) that MP Megs is able to be legally owned in Victoria (where it is considered an "imitation" firearm) and has been for a few years now, you just need to jump through some hoops to get the Chief commissioner's approval:

http://www.police.vic.gov.au/content...ument_ID=32717

All the information is available from the links in this page, but the second last paragraph is the relevant one.

In fact I'm now not certain that MP Megs is actually banned anywhere in Australia?