Age gaps between people dating: Lisa Hartman, who played Allison, was born in 1956. 'Robert Hogan (I)', who played her married lover was born in 1933 (23 years older than Hartman), and Hooker, played by William Shatner was born in 1931 (25 years older than Hartman). Conversely Adrian Zmed was born in 1954, only 2 years older than Hartman, but he had no interest in dating her.
William Shatner and Michael Pataki appeared together in The Trouble with Tribbles (1967), with Pataki playing Korax.
In series' 5th episode of the first season Michael Pataki guest stars who had previously played the Klingon, Korax in the 2nd season episode of Star Trek TOS 'The Trouble With Tribbles'.