Watch List notes:

Parthian Kingdom. Phraates III. 70/69-58/7 B.C. Æ tetrachalkon (16 mm, 2.52 g, 1 h). Mithradatkart. Diademed and draped bust of Phraates III left / Horse standing right; before, monogram. Cf. Sellwood 36.19; Shore -; Sunrise -. Unpublished. Earthen-green patina. Good very fine.

There is one variety of Sellwood type 36.19, also without Nike behind the bust of the king on the obverse, from Mithradatkart, but with a retrograde ΣΡ. See http://parthia.com/darius.htm, PDC 47592, noted as being in the van't Haaff collection. The monogram on this coin is weakly struck, but seems to be the common ΜΘT monogram seen on coins from Mithradatkart.