undetermined Greek coin

Magnesia ad Sipylum in Lydia?, , ?.,
Æ 16 (16-17 mm / 3,16 g), bronze, axes irregular alignment ↑↖ (ca. 310°),
Obv.: head (bearded, of Herakles ?) facing right, square countermark on head: H (N?) in rectangular punch, 6 x 6 mm, Howgego 820 - 829.
Rev.: (Zeus seated left on throne, holding eagle ??).
for countermark: Howgego nos. 820 - 829 .