The other factor is, are you planning on working when you go back to Oz? If your MA is in something that will give you a chance at a decent sort of job, you might be able to use that information to your advantage.

Or use that work history from before - so what if they only ask for the last 2 years, give 'em more. Heck, when I was going for my nationality here in France, the people at the Tribunal were appalled that I claimed not to have any bills I could show them made out to both my husband and me and that we didn't have a joint bank account. They told me to come back with "anything" I could find with both our names on it. Literally the only official paperwork I could find was the registration statement for our donkeys, where it states that I am co-owner at 50%.

No kidding, the clerks jumped on this and to this day I swear it's my donkeys registrations that got me my French nationality.

Give 'em the records from 3 or 4 years ago and your diploma for your MA. Offer them job ads from Oz that indicate what you will be making when you get back there. Get a little creative - it sure can't hurt!
Cheers,
Bev