Watch List notes:

Pre-reform issues, Tabaristan ('Abbasid governors). Muhammad (the future caliph al-Mahdi). AH 146-148 / AD 763-765. AR Hemidrachm (25mm, 1.94 g, 8h). Tabaristan mint. Dated AH 146 (in Arabic) (AD 763/4). Obverse: naming al-Mahdi Muhammad before bust / Reverse: naming Rawh b. Hatim to left of fire-altar. Malek 53; Album S73. Scraped in third quadrant of obverse margin. Good VF. Extremely rare.

Ex Baldwin's Islamic Auction 19 (25 April 2012), lot 4.