I'm going to plead old age and alzheimer's, but can anyone recall the nomenclature for ragwire?

Bob

It essentially ends with RH and RHW. Rubber, or synthetic rubber, insulated with an outer covering that was commonly a cotton weave impregnated with bituminous compounds. At the stripped end, the cotton would fray, hence, "rag".

Al

Seems to be exactly what was used in Austria for any type of wiring up until the mid-1950ies. Single wires, 1mm2 tinned copper, either directly buried in plaster /laying loose on the lathes in plaster and lathe ceilings, or in conduit. All a brownish-black color, makes for stinky and black fingers in any rewire (half of the house I live in is wired with that stuff and I replaced lots of it). Should be fused 6A, in most cases overfused up to 16A, typically 10A. Connections either twisted and taped, or conductors looped around a short screw and secured with nut and washer. One of those screw-and-nut connections started arcing shortly after we moved into our new appartment.

Is that what was used after the Knob-and-Tube era, (aside from metal-clad/armor-clad/BX) before the plastic jacketed "ROMEX" came into use?