Yes you can iron Australian notes, always place the note between a sheet of thin material and iron briefly letting the note cool down between irons if once isn't enough, so as not to directly heat the note otherwise it will cause damage. The plastic notes however fade slightly.
The Australian coins, the Australian anthem and the Australian notes.
It would depend on the condition of the notes, but generally, the 1975 notes are worth more.
No piano notes have been written for Iron Maiden songs.
Someone can find some Australian notes in Australia as they are used as banknotes there. Information and pictures of Australian Banknotes can be found online on a site called "AustralianBanknotes".
the plastic Australian notes are made out of polymer
The first Australian One Dollar notes were issued in 1966 at the introduction to decimal currency. The last Australian One Dollar notes were issued in 1982. They were replaced with a One Dollar coin in 1984 and progressively withdrawn from circulation.
To reduce the chance of counterfeit notes and also to make the notes last longer.
Plastic (polymer)
The Reserve Bank of Australia advises that there are approximately 132,600,000 Australian Twenty Dollar notes in circulation as at 30th of June, 2009.
There were no 1968 Australian Five Dollar notes printed.
There were no Australian Fifty Dollar notes printed in 1984.
Iron Maiden sheet books are available online.