David Janssen and William Shatner were both born in March 1931, Shatner on the 22nd and Janssen on the 27th.
Nine years after this, Julie Sommars reunited with David Janssen for the first episode of Janssen's fourth TV series, Harry O: Gertrude (1974).
This is the second of two appearances Norman Fell makes in the series, each time appearing as a police lieutenant.