Watch List notes:

MOESIA. Istros. Circa 313-280 BC. Drachm (Silver, 18 mm, 5.65 g, 2 h). Two facing male heads side by side, one upright and the other inverted – a tête-bêche pair. Rev. ΙΣΤΡΙΗ Sea eagle standing left on dolphin; below dolphin, monogram of ΠA. AMNG 419. HGC 1802. SNG BM Black Sea 242 var. A toned example.

From an old Swiss collection formed way before the 1990ies.