Watch List notes:

EGYPT, Alexandria. Marcus Aurelius. As Caesar, AD 139-161. Æ Obol (17mm, 3.45 g, 12h). Dated RY 21 of Antoninus Pius (AD 157/8). Bareheaded, draped, and cuirassed bust right, seen from behind / Hawk standing right, with wings gathered, crowned with shkent; L K A (date) in fields. Köln –; Dattari (Savio) 9075 (RY 20); K&G 37.92 (RY 20); RPC IV.4 Online 13925; Emmett 1913.21 (R5). Dark green patina, light roughness. VF. Very rare, only three known to RPC, none at CoinArchives.

RPC notes that year 21 was recut from year 20 dies by simply adding the A. All coins of both years are extremely rare with RPC only recording three from each year, none at CoinArchives for either year.