Thank you folks, I'm pleased with how it turned out but to be honest I struggled to finish it more than anything in a while. I'm not sure why.
Oh, dear, they are actually RAN roundels not RAAF ones, mate. Not your fault. They have the little white ring around the outside which is a mark of the RAN version of the roundel. 
I thought it was weird Hawkeye included it on the sheet. There were enough white circles to go under all the roundels and I figured it was for a reason!
Not your fault mate. Not many people know the difference and I wouldn't expect you to. It's an odd, minor marking difference between the services and as Guy points out, it's even more obscure than even I realised, being limited to RAN choppers mainly. I always just understood it was how the RAN marked it's planes. I know I've personally been guilty of using RAAF roundels on RAN aircraft because I lacked the RAN ones. Anyway, it's a nice plane. Well done.
