That's the coin -- many thanks. Funny how the "probably" disappeared from Jenkins' text.
He wrote: "The fact that he [the first living person on a coin] is a Persian and not a Greek is, if anything, an advantage for it has been possible to isolate the occasion and place; it was a coin minted for the
satrap Tissaphernes at
Miletos in 411 B.C., in order to pay a subvention to
his Spartan allies." (p. 103)
If the specimen is unique, and wasn't found at Miletus, and no other information is available about it, it would seem to me that the "probably" is certainly warranted, and maybe even "perhaps" or "conjecturally." (And if it is unique, well, Tissaphernes paid off the Spartans pretty cheaply: just one tet.)