Electrical issue.

[eighteenninetytwo]

Seems I had two separate issues. I found a short circuit and some melted wire cover in a wire that went to a button for the gauge cluster. Contact with metal (or poor installation) had worn through the insulation so the wire touched the metal plate as it passed through. It had got hot enough to melt 4 inches or so of wire insulation, hence the smoke I saw. This lower bit of the dash had been loose for a while.

The running / stalling at low revs choke issue had started a few days before the burning thing so I suspect they aren't related but just happened along at the same time.