I didn't use Trekcore for this scene either, as it only gave a very general selection of images.
I accept your point about the hand rails appearing to be unusually long for a 2-section (3 post) variant, but that could just be a trick of perspective. The key for me is how close Kirk is standing to Spock - looking at the layout on the
Catspaw image I posted earlier (and your
Obsession image with Chekov leaving), Kirk seems like he ought to be located much further to the right in the
Space Seed image.
However, with all the tight camera angles and limited images I'm perfectly happy to concede this point as inconclusive. We have other examples in any case