
I looked your coin up in Waddington's "Recueil General des Monnaies Grecques d' Asie Mineure", tome premier, troisieme fascicule (1910), page 523, no 56, plate XC,15, and there it was ! It is even listed as an AE 18. The dies are very close (certainly the same hand) but, as I am sure you realise, comparison is not easy. The reverse description is (translated): "Eros being carried by a dolphin, r." There is also an M, indicating the location of the coin, which, in my opinion, refers to Munich (Mionnet is given as Mi).
I do not regard it as wholly inconceivable that [this] reverse type portrays Palaemon (for whom see Roscher iii,1262; J.G. Hawthorne, TAPA 1958, 92) and alludes by way of his mother Leucothea to the moneyer's nomen.
Lucretia 3 (Crawford 390:2)
[This] type may refer to an ancestor, C Lucretius Gallus, who in B.C. 181 was created duumvir navalis, and later commanded the fleet against Perseus of Macedon.