Watch List notes:

ATTICA, Aegina, (456-431 B.C.), silver stater, (12.40 g), obv. land tortoise with segmented shell, rev. incuse square of large "skew" design, (S.2600, Meadows Aegina Group IIIb, BMC 149, SNG Delepierre 1774ff, Dewing Collection 1683, Millbank Pl.2, 13-14, SNG Cop. 517, HGC 6, 437). Partially toned, nearly full flan, with banker's mark on obverse, very fine, very scarce in this condition.

Ex Gorny & Mosch, Munich Auction Sale 122, March 10, 2003 (lot 1332).
Interestingly CNG Triton XXII, 8 January 2019 (lot 223) sold an example with edge split in extremely fine condition for $30,000.