Past November number of an
Italian numismatic magazine, Cronache Numismatiche, has a brief paper dealing with some specimens like your. Three of them are pictured (just the
face with the galley, of course).
The letters above rowers are MPV, NPV and MAD;
weights between 0.5 and 1.60 g
The author, Mario Ladich believes they were produced at
Ostia because of a note following the
tesserae indicates they were found around
Ostia. He also believes they can be roughly dated late I cent BC - early I AD.
He quotes two catalogues:
- Munzen and Medaillen AG,
Basel n.
catalogue 502 (1987), 2 specimens
- Italo
Vecchi, Nummorum Auctiones n. 15 (1999), 1 specimen
They are probably
part of a larger series consisting of other
types like
horse,
dolphin, .... all with the same square shape.
I'm sure rugser and yafet rasnal know much more than this on the subject.
Luigi
PS: The illustrations of Ladich paper are small, but i can show if of interest