Not sure if this is the manufacturer's site or a worldwide distribution arm, but you might try . . .
info@motoauthentics.com
. . . to see where you might find them in the overall MC distribution network down under.
Interesting little helmet. I saw a Nolan helmet, similar concept - pilot type of helmet - which is supposed to be very good for warm weather riding. It's the N43. Couple of different variations on these, as I understand it.
Good luck.