What Jewellers did you take it to?
Unfortunately I am in Tassie so I don't know any Jewellers in Perth but one thing I have learn is stay away from the chain stores!
I took a ring into Prouds to have it valued and they were completely useless!
Try smaller, specialty jewellery stores, ones that custom make their own jewellery on the premises.
Below is a link to a site about gold jewellery and it has what the European markings mean, I hope it helps.
If you are having a hard time reading the markings get an old tooth brush and gently try to clean out the symbols or if you are game try a needle so you can read them better.
Gold Jewelry - How to Buy Gold Jewelry