Ok thanks for that info! That may help others.. I mean to me honestly I have dug colonial and 19th c. pewter/lead,etc here in America like rosettes,buttons,different kind of decoration pieces,etc and depending on the material it is made out of,etc! It comes out looking as worn as the artifact in question you have! Now I do not know much about The Land Down Under artifacts,etc and what the soil does to artifacts over there. But if you dug this in a place that was occupied by 3,000 migrant workers in the 1950s and 1960s then HEY it must be from that time period right? Or maybe just maybe there was earlier activity on the site you are hunting that dates wayyyy back in time or MAYBE one of the workers had a ancient piece of artifact for good luck they carried with them and lost it? get what I'm saying? I do not know honestly what you have but it looks interesting and old and worn out but again I really hope someone can ID this for you because I would love too know what it is myself! Good luck.