Countermark

https://rpc.ashmus.ox.ac.uk/countermark/300 
GIC 173
bust r.
Rounded punch, could also be described as oval 
3 x 2 mm 
 

Coins with this countermark

Number Image TypeNumber CoinNumber VolumeNumber
RPC III, 607 Show 607 12 3
RPC III, 607 Show 607 13 3
RPC III, 608 Show 608 7 3
RPC III, 608 Show 608 3 3