I thought it was an interesting coincidence that in the 1949 movie Kind Hearts and Coronets Guinness played several members of the D'Ascoyne family, the hereditary Dukes of Chalfont — while in this movie as George Bird on his Last Holiday he meets an inventor named Chalfont.
shareAn amazing lot of names in English books, plays and films come consciously or not from looking at the map on the London Underground rather than at your fellow passengers. In this case, the relevant station on the Metropolitan Line is Chalfont & Latimer.
shareMany thanks.
I had no way to know, since I've never had the pleasure of visiting the U.K.