If the inside of the two compartments are in decent shape and the door hinges are solid with good looking door seals, I would replace the cooling unit with an Amish Heavy Duty built cooling unit along with a new Dinosaur Control Board.
If you want to replace it with an apartment size fridge then use the AJMadison
web site to look for one that will fit into the space where the Dometic RM3862 sits now. You can search by size.
The dimensions of what you have now are listed on this web site.
Products - Dometic
Dr4Film ----- Richard