I did not know about that!
Wherefore can this trivia be found again?
I do know that the first person to make appearances as a Klingon, Romulan, and a Vulcan was Mark Lenard.
He played Sarek (Spock's father) a Romulan in "Balance of Terror" and he was the Klingon Commander in TMP.
I also know that Jeri Ryan (7 of 9) turned down the role 4 times before she accepted. Even then, she only accepted because Jeri Taylor got on her nerves by constantly asking her!
_________________"Anyone without a sense of humour is truly at the mercy of the rest of us."