Thanks very much for the photos.  I now know to keep an eye out for that iron-coloured markings - I don't know why I never guessed they were mould, rather than just dirt spots or insect stains.
The house seems much cleaner and I already have a list of areas for detailed cleaning over the next few weekends.  I didn't realise how much the mould issue had made me feel overwhelmed and scared to clean! 
I transferred the money into your account yesterday, so hopefully you'll receive confirmation soon.
Thanks to you and Andy for all your assistance
Brisbane Qld
9 Jul 2014