I recently picked up an older Dometic 3 way fridge
, I believe it was built in 1982. I went looking for parts, and did not have much luck. I contacted Dometic and they no longer carry parts that far back, tried a local appliance parts place, same story, no luck. Personally, I'd try to take it a part (take pics!) and give it a good cleaning. Maybe talk to someone who services furnaces/gas appliances. Hopefully someone else might have a source or suggestion. Good luck!