Assuming you are referring to these?
http://goo.gl/3cngwC
Try measuring the L x W dimensions of your plates and see if any come close to the number plate types listed. Because these mounts are made specifically for AUS plates screw holes might not match up so this is something you might need to take into account.
Philip is a very easy to deal with so if he hasn't responded just yet, I'd try again. His a busy guy.
I've got both front and rear mounts with covers and while expensive worth every cent.