Nick , for a good idea on the variety of spitfires used by the RAAF you can go to the Red Roo website and have a look at the decals that Gary Byk has produced.
http://www.redroomodels.com/
You will find that the RAAF used MkVc, MK VII, Mk VIII, Mk IX, Mk14E and thats just those covered by decals produced by Gary at RedRoo. Aeroimage Works also produce decals for RAAF Spitfires so have alook there for inspiration as well.
http://www.aeroimageworks.com/products.htm
Darren , thanks for looking at those decals, pity they are all gone and no longer prduced no matter what the scale. Maybe there might be an opening for Red Roo or someone along those lines to produce them.
I managed to see my nephew today, he is a big lad, 11 lb (bit under 5kg).