Ordered new igniter, which was most likely problem -- and also the only part still manufactured which might address the problem: alternative was a new stove.
Then I followed directions of those who went before me. It went pretty much as predicted. When removing the wire nuts (They were not ceramic. The previous owner must have done this before me.), the freed wire almost slid back into bowels of the oven: beware. Other than that, and a lot of worrying, it was an easy repair.