Despite playing an elderly woman in a retirement village, Stephanie Cole was only 48 years old at the time of the first series in 1990.
The role of Harvey Baines was written for a fat man in his 50s.
Michael Bilton who played Basil Makepeace died after filming of series 4 was complete. His absence from the Christmas Special and future episodes was explained by saying that he'd gone off on an Icelandic Wife Swapping Cruise and decided to stay in Iceland to pursue women.
The "tunneling out of Colditz" movie, that Tom most frequently pretends he's part of, is The Great Escape (1963).
Paddy Ward, who played Jane's grandfather Jamie, was just 28 years older than Janine Duvitski, who played Jane.