Alexander The Great of Macedonia - Greek Silver Coin

I have heard a lot of different opinions about this Alexander The Great silver piece, some say it is a truly rare greek coin, others say it is a medallion or medal but recently made, and etc.

Unfortunatly i have little knowledge on this item. I know it was given to a very known professional european football player and i later aqquired it from his personal collection for myself and it came as a fob. I don't know what it was before if a medallion or a coin, if legit or reproduction. I find it very unique, attractive, and with detailed design.

Note: The small ring used to hang the coin/medal is sterling silver made and it was post applied. It is not made from the same silver as the coin itself. The coin/ medal is made from a less pure silver (test confimed), wich suggests an older or antique silver but not necessary ancient (?). I personally think it is logic that when it is a known reproduction piece it is a fine obviously sterling silver with contrast. To not be made in 925 sterling silver makes me think that it is either a fake meant to pass as an original or an original that went to someone who decided to apply the ring to use in a pocket watch instead. It is truly a mistery for me..
Once i don't use or collect pocket watches and the only i have is a modern Hebdomas, i have alternately been using it as necklace charm.

Any help will be appreciated.
Thank you.

Measures aprox - 2,5cm /
Weights aprox - 10 to 11gr