Watch List notes:

NORTHERN SONG: Xi Ning, 1068-1077, AE cash (3.63g), Hunan Province, H-16.181, clerical script, heng above on reverse, cast at the Xining mint in Hengzhou, Fine, S, ex Zhao Quanzhi Collection. Mint marks on Northern Song coins are generally quite rare, such as on this example.

Estimate: 75-100 USD