This is the stamp in question:
The cancel seems to obscure what seems to me to be extensive damage n the top left corner, where there are little squiggly white lines all over the place (see, for example, above the 'U' in 'AUSTRALIA':
The 'roo also looks a little odd, in fact I think I can see a little joey in there:
I'm wondering if this is a listed variety. Does anybody know?
Thanks for looking!