Help With Identifying A Medallion Please.

Thanks very much for that info Sap,much appreciated.
Quite a bit of reading to do there which will keep me busy for a while,Thankyou.

I would assume them to be simple differences in the way they were made, and perhaps wear can explain some of the lack of detail, too - the one on Zeno seems to have been polished to death.

These have no doubt been produced over many decades, and they wouldn't have used the same dies, or even direct copies of the same coin. The design would have been copied onto new dies, by hand - these aren't coins, so didn't need to pass close scrutiny to make sure all the details lined up exactly.

Still, "fakes" of this series do exist; I don't have the Cribb "Magic Coins" book, so I don't know much more about the series than what I read about them on places like Zeno, but the Southeast Asian magic coins main page does list several of the types as "modern imitations".