Cyril Fletcher (Cyril Clarke) and Betty Astell (Betty Clarke) were husband and wife in real life. They were married from 1941 until his death in 2005.
Cardew Robinson recalled the production being the scene of many mischievous pranks, culminating in an irate Jon Pertwee hurling a water-filled fire bucket at him and Harry Fowler (in response to them imprisoning him in a room); the water soaked through to the production office below, drenching paperwork.
Audrey White's debut.