Good thing you are a jack of all trades because your going to need all of them. I love messing with the RV myself for sure. Some things can be replaced and fixed others will have to be replaced. There is not to many things you can do to an RV refrig except throw it out and get another one. Or you could turn it into an ice box. Its just the nature of the beast. You can try taking it out and turning it upside down or make sure there is no cob webs in the tube. make sure it's actually getting heat from the propane. but if the ammonia has leaked out or the boiler is bad your just out of luck on that one so don't spend too much time with it just get another one and move on. Have fun fixing it up then have fun using it