I went back to take a closer look before ordering any parts. Good thing I did. I snipped off the old connector, and then snipped it again due to the corrosion in the center piece below, and discovered that the wire gauge is only about 18 and the insulation is thicker than I thought. I think I have plenty of these lower gauge connectors so I shouldn't need to order anything.

But, after I cleaned up the male lug on the thermostat a little, I didn't like what I found. Unfortunately that thermostat was a $150 part but isn't available anymore anyway.

My current plan is to put everything back together and hope for the best. If the thermostat is failing, it'll just fail and that'll be the end of it. If the repair holds, it will have cost next to nothing except my time.

 

Sounds like a plan.

 

Well here's the repair. I had scavenged a wire with the right connector on it (the red one in the photo) from an old dehumidifier, so I cut into that and soldered it to the oven wire (black). Despite the fat insulation the conductor in the red wire was not quite as fat as I'd hoped, maybe 20 gauge instead of 18 gauge. Since it's only a few inches long, I decided we'd just have to live with it. I was more concerned about that male connector on the thermostat in the photo above. I put two layers of heat shrink on the joint in the photo..

Bottom line, it's all back together and working. So I declared victory and ran away!

 

Well here's the repair. I had scavenged a wire with the right connector on it (the red one in the photo) from an old dehumidifier, so I cut into that and soldered it to the oven wire (black). Despite the fat insulation the conductor in the red wire was not quite as fat as I'd hoped, maybe 20 gauge instead of 18 gauge. Since it's only a few inches long, I decided we'd just have to live with it. I was more concerned about that male connector on the thermostat in the photo above. I put two layers of heat shrink on the joint in the photo..
View attachment 123899
Bottom line, it's all back together and working. So I declared victory and ran away!

Looking at the picture the black wire seems to have a high temperature insulation and the red wire dos not. This worries me that the red wire's insulation may melt and cause a safety issue.

 

Looking at the picture the black wire seems to have a high temperature insulation and the red wire dos not. This worries me that the red wire's insulation may melt and cause a safety issue.

Yeah, it's a fair concern. The red wire did have "high temp" or something like that written on it but I think the temperature rating was 105°C. That's a lot for me and you but not great for an oven wire. I did tell the owner to never again use the self-clean function.