Countermark

https://rpc.ashmus.ox.ac.uk/countermark/1458 
GIC
uncertain in square punch
square 
variable 
 

Coins with this countermark

Number Image TypeNumber CoinNumber VolumeNumber
RPC V.2, — (number not assigned), type ID 28114 Show 3419 5 5.2
RPC I, 942 Show 942 3 1