I know that my grandfather's grandfather lived in Safi in Morocco in the 19th century. I don't know his name at all, but I do know his wife's given (first) name. I also know that he was British - either born in Morocco or immigrated to Morocco. They were most likely Jews and he was a shop owner in Safi.
How would you go about looking into British records of citizens living abroad in those days? It would be best to find business records or marriage records.
As I'm Israeli, it's difficult to visit Morocco to find answers, so I'm hoping to find answers through foreign governments. I think, and correct me if I'm wrong, Safi was under French rule at the time - would the French have any records of British/Jewish citizens?