I got into the biz re-wiring my house. Found a bunch of the old linen/rubber wiring, that had ozoned to useless for the last 3-6" in each box. Inside the pipe was fine, of course.

When they upgraded as part of a grant back in the 80's, they installed a new CB panel to replace the 60A fusebox.

They upgraded with brand new THHN... right up to the first 1900, where it transitioned into the old wiring.

Never bothered to upgrade the circuit arrangement, either. A 1600 ft2 house operating on 3 circuits? [Linked Image]