This motif is more frequent on coins issued before the period of Roman Provincial coinage, e.g. a portrait of Cupid appears on the obverse of Roman Republican denarii of Cn. Egnatius Cn. f. Cn. n. Maxsumus (75 B.C.).
His portrait is also on the much rarer AR sestertii of C. Considius Paetus (46 B.C., two variants shown here, photos courtesy of Andrew McCabe).
Cupid is likewise on Æ from Tyndaris in Sicily (3. cent. B.C.) and Aphrodisias(-Plarasa) in Caria (1. cent. B.C.), and on very scarce Æ coins of Mithradates Eupator from Amisus in Pontus (obverse illustrated) and from Sinope in Paphlagonia.
But the most often encountered portraits of Eros are on Æ of the 2. cent. B.C. Seleucid kings Antiochus VII, rev.: headdress of Isis; Alexander II, rev.: anchor; and Antiochus IX, rev.: Nike.
Obverses of coins of Antiochus VII...
Æ 15, 9 h, 2.75 g. Obv. Bust of Eros l. Rev. Bunch of grapes with leaf (from a private collection, photos by permission).
* The bust of Eros also appears on a small silver gem of the Roman period (1.-3. cent. A.D.) (Gorny & Mosch, auction 208, 2652, photo courtesy of Lübke & Wiedemann KG, Stuttgart).
* A male bust which may represent Eros can be found on the obverse of a crude lead tessera of uncertain date, probably from Rome, with reverse type of Aphrodite half-clothed and wringing out her hair (F. R. Künker, auction 124, 9457; Fritz Rudolf Künker GmbH & Co. KG, Osnabrück, http://www.kuenker.de/, photos courtesy of Lübke & Wiedemann KG, Stuttgart).
Ilistra / Antonine period
References: RPC IV, 7245; Imhoof-Blumer, Kleinasiatische Münzen, 1