Watch List notes:

Augustus. 27 B.C.-A.D. 14 AE dupondiius (26.3 mm, 8.19 g, 4 h). Rome mint, struck 17 B.C. C. Cassius Celer, moneyer. AVGVSTVS / TRIBVNIC / POTEST, legend in three lines within oak wreath / C CASSIVS CELER III VIR A A A FF, legend surrounding large SC; AVG countermark. RIC 376; BMCRE 169; Countermarks: Pangerl 75. Fine. 

Countermark: AVG in rectangular punch