When Captain Mainwaring says "The love of a man for a woman waxes and wanes like the moon, but the love of brother for brother is steadfast as the stars," he is actually quoting an Arabian proverb, although he probably remembers it from the foreword to the film Beau Geste (1939).
The Mainwaring's home telephone number is given as Walmington-on-Sea 92.
The opening scene features the platoon watching Conquest (1937) at a cinema and subsequently perform Charles Boyer impressions on the bus ride home. John Le Mesurier had an uncredited cameo role in Casino Royale (1967) as a M's chauffeur who drove M and a number of international spy chiefs including Boyer to meet the retired Sir James Bond.