Watch List notes:

Anonymous. 189-180 B.C. AE as (35.6 mm, 33.30 g, 1 h). Rome mint. Laureate head of Janus, I above / ROMA, prow of galley right; bull and MD monogram above; I to right. Crawford 142/1; Sydenham 299. aVF, flan chip, overstruck. Rare. 

Ex RBW collection (not in previous sales). 

Janus' head appears to be within a wreath, indicating an overstrike. The under-type is uncertain.The meaning of the MD monogram is uncertain but may represent the moneyer’s initials, M. Durmius is one possibility.