Black Jack (1979)

 

A French sailor escapes hanging and teams up with young Stephen Hirst and, late Louise Coope a young girl committed by her parents for her eccentric behaviour.

From memory: Endearing and charming children's adventure convinces with a good cast, excellent period details and especially Chris Menges' beautiful cinematography. 

Halliwell (no star): "The purpose of this costume adventure, from these creators, is obscure, but the execution of it is muddled and amateurish."