He played Winston Smith in Theatre 625: The World of George Orwell: 1984 (1965), a remake of Nigel Kneale's adaptation of the novel.
He also had a role as Royal Air Force Squadron Leader David "Scotty" Scott in the film Mosquito Squadron (1969), with David McCallum, in which his character is shot down during a low-level bombing raid over Northern France in 1944 and assumed killed.
Buck portrayed Dr. Watson in the 1978 BBC Radio 4 series of 13 Sherlock Holmes short stories.
At the time of his death, he was married to the actress Madeline Smith, who featured in the film version of Up Pompeii (1971) and numerous comedy programmes in the 1970s.
In 1968, William Heinemann published a 'funny and off-beat' children's book written and illustrated by Buck entitled The Small Adventures of Dog.