Gerd R.
Stumpf, Numismatische Studien zur Chronologie der römischen Statthalter in Kleinasien (122 v. Chr.-163 n. Chr.), 1991, pp. 13-17:
Snake on staff must indicate
Pergamum as
mint, similar coins with
snake emerging from basket must have been struck in
Ephesus.
Previously unanimously attributed to L. Antonius, who was
quaestor under the governor of
Asia Mincius Thermus in 51/50 BC, and functioned himself as governor between Thermus' departure and the arrival of the next governor.
But there is no L in the
monogram, so it can't be L. Antonius. The
monogram can however be read as including the letters MA ANTONIV, according to
Stumpf.
According to
Stumpf the only possibility is M. Antonius,
Consul 99 BC, who served as
quaestor in
Asia in 113/112 BC, and at some point during
his term of office there also
had the powers of a
praetor, according to an
inscription from Delos.
This sounds plausible, but I haven't studied
Republican cistophori and don't know whether Stumpf's suggestion has ben generally accepted or rejected by other scholars.