Dometic series 52 Refrigerator

[smokey 8866]

I inherited a 1965 Airstream safari land yacht after my grandfather past. It has been sitting in his backyard for 40 years. The refrigerator dose not get cold just cool when running it off of propane or electricity. I think I may have to replace it. I don't know enough about travel trailers. What would be a good replacement for Dometic series 52 Refrigerator? I don't want to do anything thats going to affect the value of the airstream. Thank you for any help with the restoration.