Gerald James (Harry Costigan), Brian Haines (Billy Bennett), Donald Oliver (Frank Harrison) and Gerald Lawson (watchman 'Pop' Prendergast) reprise their rôles from Has Anybody Seen Costigan? (1963). James Elliott and Maureen Costigan were recast.
Brian Murphy and Larry Dann get an addition credit: "now appearing in 'Oh What a Lovely War' at the Wyndhams Theatre".
Gerald James gets an additional credit: "now appearing in the Harry Secombe musical 'Pickwick' at the Saville Theatre".
Tenniel Evans gets an addition credit: "now appearing in 'Portrait of Murder' at the Savoy Theatre".