Cast list

I know Celia Imrie is an established actress, and is one of my favourites, but why does IMDB have her so high up the cast list when she is only on screen for a few minutes?. Also, where is the name of the youngest daughter?.Also, why is the name of Annette Crosbie's character missing?. Also, 2 uncredited actors-the actor who played the deaf relative who had come from New Zealand was Robert Riach, who played TV John in the sublime TV series Hamish Macbeth; the other uncredited actor was the one who played the police sergeant-I recognised his face but couldn't put a name to it-I think he was the guy who played the roadie in that other sublime TV series Tutti Frutti. Can anybody help with his name, please!.