This outfit was a re-creation of one seen in the TV movie Genesis II, a project that Gene Roddenberry did after the original Star Trek was cancelled.
At one Rovacon, Thomas went on stage wearing this outfit, and Renfield wore a Star Trek: The Next Generation uniform. The two of them argued about whose TV show was the true successor to Gene Roddenberry's legacy. Then Thomas threw a punch and sent Renfield sprawling.
They called the presentation "Genesis 2, Star Trek 0."