There are some that are inspired by a real person. David Gold and Mor glasch Tev of the S.C.E. are heavily inspired by the characters of Sherman Potter and Charles Emerson Winchester III and the manner in which Harry Morgan and David Ogden Stiers, respectively, played them. President Nan Bacco is based on my great grandmother. Lieutenant Lokor of the Gorkon is pretty much Keith Hamilton Cobb.
All this is by way of leading up to the fact that there are two characters in Star Trek: A Singular Destiny for whom I had particular people in mind cast in the role.
First off, the template for Sonek Pran is Arlo Guthrie, best known as a folk singer, but also an actor (he appeared as himself in the Alice's Restaurant movie, appeared in an episode of Renegade as a fugitive, and was a regular on the short-lived 1990s series The Byrds of Paradise). Arlo's a Star Trek fan, and he and I exchanged e-mails a while back, and when I was developing the character of Sonek (a character type that I've had in my head for a while, to wit, someone who functions entirely on the strength of his words), I realized that he was Arlo -- well, kinda. In any case, he's who I had in mind.
The other one is David Nykl as Bojan Hadžić. I was originally going to use the da Vinci as the S.C.E. ship dealing with Maxia Zeta, but then terri_osborne -- who is much smarter than me -- pointed out that using the da Vinci on top of President Bacco and the Gorkon was getting a little too self-indulgent (even for Mr. Self-Indulgent Me). So I switched to the Musgrave, keeping Stevens as a familiar character. Given the similarities between the S.C.E. and the Stargate franchise, I thought it might be fun to see what it would be like if my favorite Stargate character, Radek Zelenka from Atlantis (played by Nykl), served on an S.C.E. ship. So Bojan Hadžić is pretty much Zelenka transported to the Trek universe.