Poly et le secret des sept étoiles (1964)

Tony takes his horse Poly to Corsica to visit his aunt Antonia Calvi and cousin Stella who have fallen on hard times. He soon makes friends with a local fisherman called Dominique and a kindly old scientist, Antoine. The three friends find themselves pooling resources to protect Antonia and Stella from a local brute who has made them homeless. It turns out however that the Calvi family may not be so poor after all when a mysterious family medallion offers an unexpected route to great fortune.