> For the record, knob and tube was considered obsolete before WWII.

Perhaps, but my home, originally built circa 1952 (in California) was
straight knob and tube. With much remodelling over the last 30 years, I
have exactly one interior wall between two bedrooms, with a k&t run in it.
The rubber insulated wires go straight up the wall into the attic, and
into a steel junction box, where they are wire-nutted to Romex.

Dave