Ok, found out who the Australian Distributor for GMA actions is.

Centrefire Australia.
www.centrefireaustralia.com.au

Robert O'Reilly
PO Box 3492,
Tannum Sands QLD 4680

Phone - (07) 49 733535

Same guys that produce the Diesel and Dust magazine apparently.
Website is not much help on the actions, but does show they have them, so maybe an email might be in order if interested.
DC