...As is true of so very much of life. Sorry for the borderline hyperbole, but as a recovering Philosophy major, that's what landed on me first.
Parthicus, Many thanks for the helpful info & the links by Tom Mallon ! I acquired my drachm many years ago strictly as a whim during a multi-coin trade deal with a dealer who knew nothing about the coin. The coin's mint state condition sucked me in. The Pahlavi script has a flow or ebullient rhythm, like so many Mideastern scripts, that isn't seen in other formal languages. So different calligraphers writing the same thing may show differences because of personal style. The next time I pull the coin out of a safe deposit box I'll attempt to translate the other letters after using some eye drops . The luster on my coin makes it more difficult to translate from my photos. With the coin in-hand I'll attempt to draw the characters by holding it at an angle & go from there .
There is an extensive book revue of a museum catalogue of late Sasanian coins that is worth having even if you do not wish to buy the book. https://www.academia.edu/14957074/Late_Sasanian_Coinage_and_the_Collection_in_the_Muzeh_Melli_Iran