Margaret Rutherford and Alaistair Sim - Shenley Road, Borehamwood, Herts, UK - Blue Plaques on Waymarking.com

The IMDB website tells us about Margaret Rutherford:

One is always at pains to locate a reference to Margaret Rutherford which does not characterize her as either jut-chinned, eccentric or both. But such, taken together, made for the charm of the woman. The combination of those most mundane of attributes has led some to suggest that she was made for the role of Agatha Christie's indomitable sleuth, Jane Marple, whom Rutherford portrayed in four films between 1961 and 1964 plus in an uncredited film cameo in The Alphabet Murders (1965). Rutherford began her acting career first as a student at London's Old Vic, debuting on stage in 1925. In 1933, she first appeared in the West End at the not-so-tender age of 41. She had her screen debut in 1936 portraying Miss Butterby in the Twickenham-Wardour production of Dusty Ermine (1936).

In summer 1941, Noel Coward's Blithe Spirit opened on the London stage, with Coward himself directing. Appearing as Madame Arcati, the genuine psychic, was Rutherford, in a role in which Coward had earlier envisaged her and which he then especially shaped for her. She would carry her portrayal of Madame Arcati to the screen adaptation, David Lean's Blithe Spirit (1945). Not only would this become one of Rutherford's most memorable screen performances - with her bicycling about the Kentish countryside, cape fluttering behind her - but it would establish the model for portraying that pseudo-soothsayer forever thereafter. Despite Rutherford's appearances in more than 40 films, it is as Madame Arcati and Miss Jane Marple that she will best be remembered.

The IMDB website tells us about Alaistair Sim:

The son of Alexander Sim JP and Isabella McIntyre, Alastair Sim was educated in Edinburgh. Always interested in language (especially the spoken word) he became the Fulton Lecturer in Elocution at New College, Edinburgh University from 1925 until 1930. He was invited back and became the Rector of Edinburgh University (1948 - 1951). His first stage appearance was as Messenger in Othello at the Savoy Theatre, London. He went on to create some of the most memorable (usually comedic) roles in British films from 1936 until his death in 1976.

He came to acting late being 30 when he started acting on the London stage and 35 when he made his film debut. In the late 30's he was inclined towards the sinister with such films as 'The Terror'(38) although he also appeared in the Crazy Gang's 'Alf's Button Afloat' (38) and with Jesse Matthews in 'Climbing High'(39). During the war he played Sergeant Bingham in the 'Inspector Hornleigh' films directed by Walter Forde. It was after the war that he found his true forte - comedy - in the films of Launder and Gilliat in particular playing a series of Dickensian eccentrics, rogues and pathological assassins although the sinister element often remained. Despite his many films his attachment to the theatre continued throughout his career, acting, directing and producing and with a strong association with James Bridie who wrote seven plays for him.