If the coin is the right size and weight, and you are still unsure, then just test the sound. There is no known way to make a counterfeit coin that will be even close to passing all three tests (size, weight, tone) at the same time. Thanks for that! My Australian Mint Kangaroos had a beautiful ring...

There are private safety deposit boxes in Pattaya. A private vault company in Bangkok. However, I wouldn't store gold in Thailand or any third world country. If I remember the PP book also recommends against it. Store it in a nearby stable country. Singapore would be a good option for Thailand resid...