Small Greek Bronze with Helmet and Horseman [solved]

Hi!  I was hoping someone might be able to help identify a small Greek bronze coin.  It is about 9mm across and weighs 0.98g,  One side has a helmet (Attic?) with crest and the other a horseman with raised arm.  The field also has what appears to be the letters “ΤΙΣΣ” which I do not recognize.  Thanks!

Salve, provi a guardare nella monetazione di Pharsalos in Tessaglia.

Grazie! Proverò.

In case anyone still is interested, I believe that I have identified this coin:

A chalkon from Astyra (Mysia) issued under the satrap Tissaphernes c. 400 B.C.:

N#179579