My MIL's old 1950s oven died a few years back, and so she bought a new electric range to replace it. The new one never seemed to work correctly, even after visits from the repairman to replace a faulty heating element.

Last year, SWMBO and I were visiting, and she mentioned all of this. Within an hour we'd gone out to the parts store, purchased a replacement thermostat/control unit, and installed it for her.

Works fine now.. seems to keep the temperature within 20 degrees (C) of what it claims, which is about as close as one might expect it to do.

Cheers