The church used in the scenes where Mr. Paxman is talking to the vicar about the coat of arms, and sees the figure of ghost, is St. Mary's Church, in Happisburgh, Norfolk.
Clive Swift makes one of two appearances as Dr. Black. The other is in The Stalls of Barchester (1971).
The character of Dr. Black does not appear in the original story by M.R. James. Also, the character of Mr. Paxton is a much younger and rather wealthier man than than how the character is depicted here.
A highly acclaimed new version of this film was later released, under the title A Curious Tale (2021).