Countermark

https://rpc.ashmus.ox.ac.uk/countermark/422 
GIC 300
Capricorn r., star (?) above back
On reverse 

Coins with this countermark

Number Image TypeNumber CoinNumber VolumeNumber
RPC I, 2015 Show 2015 9 1
RPC I, 2015 Show 2015 7 1
RPC I, 2015 Show 2015 5 1
RPC I, 2015 Show 2015 4 1
RPC I, 2015 Show 2015 3 1
RPC I, 2015 Show 2015 11 1
RPC I, 2015 Show 2015 8 1
RPC I, 2015 Show 2015 2 1
RPC I, 2015 Show 2015 14 1
RPC I, 2015 Show 2015 13 1