There were three lots of special interest to Vulcanologists. The first was sketches for Perrin's (Joanna Miles) costumes in the TNG episode "Sarek."
I think Blackman did a great job with this costume. It has some touches that throw back to Robert Fletcher's movie-era work (including re-using the jewellery worn by the Vulcan maidens in Star Trek III). The bright pink makes Perrin stand out as a non-Vulcan. It's reminiscent of the bright colours worn by Sarek's first wife, Amanda, in "Journey to Babel".
The second lot also features work for the episode "Sarek." These sketches are for Sarek's aide, Sakkath (Rocco Sisto).
The third lot is sketches for Tuvok's (Tim Russ) civilian clothing. We've seen Tuvok in pyjamas a few times but these look quite similar to the costumes he wore in "Riddles" and "Endgame".