Watch List notes:

SUDAN: temp. Muhammad Ahmad al-Mahdi, 1881-1885, AR 20 piastres (23.65g), "Qustantinya", AH"1255" year "9", KM--, local imitation, similar to the 1255 year 2 gold coins (KM-3), choice VF to EF, RRR, ex Islamic Coin Auction 20, Lot 808 (May 2012), which sold for the equivalent of about $610. The key difference between the Sudan imitation and the Ottoman original is the form of the crescents around the center, as can be seen by comparing this piece with the normal Ottoman example Zeno-158126.

Estimate: 500-600 USD