Was it cast for the jewellery trade? As soon as I saw it I said it's a cast, all the wear is in the wrong places and you can see pits from high spots on the mould. It is a fair casting, but, it would never pass for a die struck coin if somebody was to take a good look at it. Fake coins are meant to pass as change, this way they go unnoticed. Casting a pre decimal means it will be immediately scrutinised, which is not what a forger wants. The colour looks a little off and the purity is high, have you taken it to a coin dealer? Fakes 'are' collectable in their own right, seeing this is a 'war years' coin two things come to mind, criminal activity, someone trying to rid themselves of silver by casting coins (would account for the purity) and lastly the Japanese produced "invasion money" notes, to be used in a conquered Australia. It remains a mystery........