https://rpc.ashmus.ox.ac.uk/countermark/120 

GIC 4

Asclepius, head r.

oval 

8 x 6.5 mm 

Pergamum (Mysia)

For the head cf. BMC pl.33, 4 (on the reverse), unless it is supposed to represent Pergamos. See GIC 238 = https://rpc.ashmus.ox.ac.uk/countermark/360.