Troubleshooting Uneven Oven Temp 1950’s Hotpoint Range

Hello ~

I love my 1950’s Hotpoint PushButton range (Cat.No. 209RC21, Serial # 9076529), but the oven is no longer heating up to consistent temperature. 

Anticipating needing a new thermostat, I’ve tried my local vintage supply company & GE, and they both say that part (WB23X5049) is no longer available.  I think I may need a thermostat because both elements work, and the thing that looks like a wire coat hanger along the back wall looks pretty black and somewhat corroded.  The oven does heat up, just not to a reliable or consistent temperature.

Before I try to find a repairman who will even know anything about my oven, is there anything I can do to identify the real problem?

Thanks!

~Tracy, the OldHouseOwner