
I've gone on and on about how incredibly not messed up our house is. I've talked about how I couldn't find one bit of dodgy electrical work, etc., etc.
Note the massive crack in the joist in the center of the picture. This joist happens to run right underneath the center of the bathtub and the shower pan in the master bathroom. Further, note that there appears to be a chunk missing from the bottom of the joist. At the point that the electrical passes through the joist, it is about 1.5 inches below the next joist over.
I don't have any way to know whether the joist was cracked or if just the piece was missing when the ceiling was replaced and the plumbing work was done, in 1967. Either way, I place the blame on whoever did the work. When presented with a joist that was so compromised, it should have been addressed.

They also saw fit to notch the joists enough to properly insulate the pipes, which resulted in two of them cracking. Further, they stuffed enough fiberglass around the knob and tube wiring to start a good fire, and closed up an electrical box in there as well.
Of course, I shouldn't be surprised by the quality of the plumbing installed by the same individuals. There is corrosion around every single fitting - and in some places where there aren't even any fittings. Not good.
As if this all wasn't bad enough, the framing under the shower pan, which was redone more recently, doesn't look too hot either.
I'd love nothing more than to replace all of this plumbing while we have the ceiling open. However, that simply isn't in the budget right now. What we'll probably end up doing is addressing the structural issues before the ceiling goes back up, use greenboard for the ceiling, and deal with the plumbing when we can.