Countermark

https://rpc.ashmus.ox.ac.uk/countermark/1375 
GIC
laureate, bearded head r.
oval 
6 x 4 mm 
on reverse; might be Antoninus Pius? similar to GIC 113, but that was always applied to the obverse, and seems different from cmk 1656 

Coins with this countermark

Number Image TypeNumber CoinNumber VolumeNumber
Show 191
Show 109
Show 127