Great find! Looks like the "Deadly Years" ladder was illuminated from below and extended "all" the way down.
Regarding the swing wall / corridor between the cabin and the briefing room / E-booth ladder set, I noticed its first appearance in a Season 1 episode ("Man Trap"?).
By Season 2 it became a regular item and is one of the few things where I really wonder, if "they" knew what they were doing (especially considering episodes like "Mirror, Mirror" and "By Any Other Name" where there seemed to be an adjacent room to the cabin bedroom and not
By Season 3 they discarded this concept (and the turbo lift "in" the transporter room) but it made occasional comebacks and - again - made no sense in "Wink of an Eye". In this particular episode the briefing room set was extended towards the cabin set and - again - there would have been no place for this kind of corridor running between both sets.