Hey there! Kitchen remodels sure can throw up some surprises, can’t they? It sounds like you’re dealing with a real classic with that Westinghouse oven. I had a similar hiccup last year when our dishwasher decided to conk out right before a major holiday gathering. Not fun!
I stumbled across a website that might just have what you need:
Westinghouse MP101 Simmerstat . They list a simmerstat that matches the MP101 model. Might be worth checking out.
Fingers crossed you get your oven sorted in time for that big family dinner. Nothing like the smell of a home-cooked meal to make a house feel like a home, especially with everyone gathered around. Cheers and good luck with the rest of your remodel!