Countermark

https://rpc.ashmus.ox.ac.uk/countermark/713 
GIC 587
CP?
rectangular 
c. 7 x 4 mm 
Buthrotum (Epirus)
Might refer to the duumviri Cocceius and Pomponius (BMC Thessaly p.97), if they were later than Graecinus (the magistrate on the countermarked coins), however the reading aninterpreation remain uncertain. 
List of countermarks View on a map

Coins with this countermark

Number Image TypeNumber CoinNumber VolumeNumber
RPC I, 1391 Show 1391 2 1
RPC I, 1392 Show 1392 1 1
RPC I, 1391 Show 1391 3 1
RPC I, 1393 Show 1393 2 1