Help with ID please..?

[GoldDiggersLtd]

Good Morning all. Please can someone shed any light on what this May have been in its prime?
Obviously it looks like a coin but I'm not sure of the letters on the back, they look like royal initials. Any help to feed my interest would be greatly appreciated. Thanks. ;-)

 

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[GoldDiggersLtd]

Looks like maybe a crown or something was on the back? Very worn tho.