Many thanks to a reader who pointed these out. We have a new set of photos of William Shatner apparently (or not) without his toupee, from the book Captain Quirk: The Unauthorized Biography of William Shatner. These are from around 1966-7 and feature Shatner (with his first wife and daughters in the lower picture, one of whom appeared in the Star Trek episode "Miri"). Whether or not Shats is wearing a hairpiece here, it is clear that Shatner was not Patrick Stewart bald during the filming of TOS, but rather Richard Nixon thinning. See here for more on that.
What you can't see from these angles, but can nonetheless sense is the lack of bulk at the top rear of the head, where the most thinning was taking place. Is the frontal hair swoosh Shats' own?
We welcome any suggestions and comments. Only with your help can we make this the definitive oracle on Shatner's toup.
UPDATE: A better resolution photo, albeit watermarked. Is this a toupless Shats?
UPDATE II: One of our earlier posts. Since publishing this piece, more toupological information has come to light, which suggests that these are indeed typical "Jim Kirk lace" images - although perhaps self-applied, hence a slightly higher hairline.