I think that might be a rumor. Star Trek was being cancelled and people knew that because Harlan Ellison’s letter of December 1966 confirmed it, nobody cared. One big rumor is that Gene signed the Intersteller Club certificates or the deluxe one? This is wrong, they were signed by his secretary (bjo answered that)
Scripts were mimeographed in house at Lincoln. They didn’t sell enough to rent a Xerox* so they kept doing the mimeographing themselves. *Copying machines of that time (from 1959) I worked on were one quarter tone and shiny, not grey or matt. In the early 1980s full tone came in which was matt. You could put a complete mimeographed script in Xerox 9400 and have them collated and the grey color was the same. What you got is copies of copies, a reason I never bought many. Many studios must have used the full tone copiers for scripts. In huge runs you would go with offset.