Welcome to the Headless Medusa Club! I've somehow managed to pickup quite a few of these over the years, none of them "perfect" unfortunately. The last two are non-Amisos - from Komana and Amastris respectively.
Congratulations on your win (x2)! I think you still did good for the Amisos piece. This is my example, I love the clear bloody body on mine: Pontos, Amisos. AE. Time of Mithradates VI Eupator, circa 85-65 B.C. Obverse: Head of Athena right, wearing Attic helmet. Reverse: Perseus standing facing, holding harpa and Medusa’s head; Medusa’s body at his feet, monograms to left and right. Reference: HGC 7, 357. 17.30g; 31mm