We've finally managed to track down actress Yvonne Craig's (the Batgirl who guest-starred in the Star Trek episode "Whom Gods Destroy") description of her sadly somewhat unpleasant experiences with Bill Shatner and his toupee as recounted in her book From Ballet to the Batcave and Beyond.
But first, Craig's overall experiences with Shats weren't pretty and the actress doesn't mince her words when it comes to her strong dislike of Bill Shatner. She describes him as "a man with little social skills" and "a completely selfish actor and a maddeningly narcissistic human being!" There's more still: "[During shooting, Shatner] not only moved me around physically for the betterment of his profile, but suggested line readings so that he could respond in a way that he had predetermined...Most actors extend the courtesy of interacting and reacting to one another! I was astonished that the director allowed this to go on..."
This is the archetypal negative Shatner portrait from numerous (though certainly not all) co-stars from this time, and we have to say that it is probably mostly true. We try to be fair to Shats as much as possible here, but at this turbulent time in his life - he was overweight, his marriage was falling apart and his star vehicle Star Trek was a flop that was going to be cancelled in a matter of weeks - he probably did act like a jerk towards a lot of people.
As Shatner himself has written: "...while I've never set out to hurt anybody, I may have, at times, been ignorant of my fellow actors' need for screen time, not to mention their feelings."
Perhaps the toup was a factor in this behavior too - the constant fear of exposure as a bald man; the adoration sought for the artificial thickly-haired image; the thing on the head needing constant attention and glue...who knows.
Anyway, now to the toupee part. Yvonne Craig describes the difficulty that her green makeup (she played a green Orion slave girl in Star Trek) caused both her and the people it was rubbing off on:
"[Shatner] blithely announced that since he was down to his last clean costume, I was not to TOUCH him! Fine with me, except for the fact that the next day we were scheduled to shoot the love scene in which I declare that I love him, therefore I must kill him.
"Wondering how I could imply hanky-panky without actually touching him or his wardrobe, I lit upon what I thought would be the perfect solution. I would just play my fingers through his hair."
William Shatner with Yvonne Craig. Image sourced here.
Craig, having finished that day's shooting, rubbed her green make-up off in a studio shower-room and then went to say her goodbyes:
"Having finished my ablutions, I stopped by the make-up room to say good night. And what I discovered made my heart skip a beat. There stood Bill Shatner with his hair in his hand! Now, there was not a doubt in my mind that if a green smudge on his costume were going to unnerve him, hair dandling with the possibility of twirling it right off his head would be out of the question. I spent a sleepless night trying to solve that dilemma. As luck would have it, the cameraman decided it could be fixed handily by simply shooting different colored lights across us (one, of course, being green) so that the audience would be unable to differentiate between a green smudge and a green shaft of light."
Craig also wrote of seeing Shatner years later on a plane during a 1997 flight from South Africa. She describes his then curly weave as "yak-like".
Yvonne Craig's website, where her book and other memorabilia can be purchased is here and to be as balanced as possible, William Shatner's website where (different) books and memorabilia can also be bought is here.