"That ramp is a lot longer than I imagined! Interesting to find out."
I have my doubts whether this is really the case. Look again at the b&w photograph, it suggests a rather steep ramp within a short amount of space and that white bottom line in the photograph is also visible in the screencap: http://tos.trekcore.com/hd/albums/1x...ehdalt0076.jpg
Looking at the video footage the people in the background passing this area get short in a very short amount of time (hence my original theory of stairs). Additionally, the door behind the A-Frame seems to have the same distance to the A-Frame as in the rest of TOS, except that it has 'sunk' into the floor.