Continuous studs behind the wall and the lack of a visible header suggest they were never open, but newer fireproofing and other oddities show that the wall had been altered; it's hard to tell for sure. If these are load-bearing, each stud will have to be wrapped in drywall.
A collage of frosted windows or other translucent material will cover these to mediate the connection of the spaces.
The central stair, which mirrors itself on the other side of this wall, will be partly opened to enable better circulation and play with lines of sight.
The tools I have won't let me slice any deeper to finish the puncture, so I'll have to finish this from the other side of the wall. Lining up the cuts won't be easy.