OP

Quoted from DCP:

That room took a beating when it was used as Piedmont's Post Office from the 1940s until about 1989. It's our pinball room now.

OP

Quoted from DCP:

Very interesting pics, Manny - these renovations force us to combine all sorts of materials and technology to make it all work. The bathroom I'm working on is a "practice ground" for every other room in the Bank. It had every possible variation of original materials and later additions and hack work.
There is drywall on top of plaster over wood lath. There's drywall on top of plaster on top of plasterboard. There is original wood lath on the ceiling with plaster. And there is plaster directly over brick.
There were "examples" of every kind of damage. Ceiling plaster coming loose from lath due to leaks, wall plaster cracking and falling off due to leaks, holes bashed in walls to route electrical wires...
I'm using multiple techniques on the bathroom to see which ones I like best. On one wall, I extended the framing and drywall up to the full 10 feet rather than tearing out a framed wall that was on top of the plaster. Mostly, I would like to avoid doing that, and go back to the plaster walls where possible.
I stabilized the ceiling with dozens of plaster washers, and removed all the loose and failing plaster. Then I covered the whole ceiling with drywall.
A mess of different materials, but it's coming out OK so far. More pics later as I make progress.