Kevork Malikyan (Chico) previously appeared in Aces High and Sometimes Very Low (1979) as Chris. Mike Savage (Dipso Pete) previously appeared in All Mod Cons (1980) as Bernie.
Last appearance of Bert Daley, played by Sidney Livingstone. He appeared in 8 episodes. The first one being The Loneliness of the Long Distance Entrepreneur (1991)
The title is a pun of the Roman Catholic belief 'The Immaculate Conception'.