Watch List notes:

ATTICA, Athens. Circa 510-500/490 BC. AR Obol (8mm, 0.53 g, 9h). Contemporary imitation(?). Helmeted head of Athena right, large pellets at bottom of crest / Owl standing right, head facing; olive sprig to left; all within incuse square. Seltman Group P, unlisted denomination, but cf. tetradrachm obv. die A324, as well as hemidrachm pl. XXIII, β and triobol pl. XXIII, γ, for the same style; otherwise, unpublished in the standard references. VF, toned. Extremely rare Group P obol.

For a discussion of Seltman's Group P, see K. Sheedy and D. Gore, Asyut 422, Seltman Group P, and the Imitation of Attic Coins" in RBN CLVII (2011). Seltman had characterized this group as imitations, but they may actually be official products of Athens. "