Hurst is the only person I can think of who was in the Classic Trek TV series and DS.
There is another. Natalie Norwick appeared in 7 episodes of DS (playing established characters, such as [spoiler]Ruby's ghost when she was summoned by the ghost of Trask to indict Barnabas)[/spoiler] and as the wife of Kirk's friend in the ST episode "Conscience of the King."
This may be my geekiest post ever.