Countermark

https://rpc.ashmus.ox.ac.uk/countermark/774 
GIC 650 i
monogram IMP
rectangular 
 

Coins with this countermark

Number Image TypeNumber CoinNumber VolumeNumber
RPC I, 2235 Show 2235 43 1
RPC I, 4392 Show 4392 28 1
RPC I, 4392 Show 4392 14 1