Watch List notes:

ABBASID: AE fals (2.93g), NM, ND, A-338, citing al-Mahdi Muhammad, the future caliph al-Mahdi (AH158-169) as the son of the caliph (bin amir al-mu'minin) // legend al-haqq al-huda wa'l-'ilm ("truth is guidance and knowledge"), unpublished, probably struck circa AH142-158, when al-Mahdi was heir apparent to the Abbasid caliphate, VF.

Estimate: 150-200 USD