This looks rather similar (but not quite)
to a job, I was doing down in the lower South Island of New Zealand, after I came out of my time, some years ago.
This job was the renovation of a Police Station, the builders took the old Fiberous Plaster linings off of the walls in the Seargents Office and on one wall, there was
a joint in there that would have been beyond the belief of any electrical person in the world.
There were a set of three brass busbars, nailed to the stud of the wall, obviously for Phase,Neutral and Earth, and from this most of the socket-outlets were fed, there were wires every where, most of them conduit wires, I wish I had have had a camera, back then.
Let's face it, these days if you're not young, you're old - Red Green