J. Warren (pp. 21-22) dates the coin most likely to the ca. first quarter of 1st century BC but cannot rule out ca. 58-30 BC, and suggests that the denomination could have been quarter-obol or trichalkon.
“Co 225 (Late Hellenistic bronze coin of Sikyon).” In Kenchreai Archaeological Archive, edited by J.L. Rife and S. Heath. The American Excavations at Kenchreai, 2013-2024. <http://kenchreai.org/ke/co0225>