Sounds like a good deal but I'd subtract the price of a new fridge from the total. These absorption boxes are not like fixing a compressor model. They are prone to have the ammonia coolant crystalize in the tubing and once that happens, no amount of TLC will make them right. It only takes a short period of time using the fridge out of level for this to occur.
If I did buy a trailer with a bad fridge, I'd replace it with a residential, taking the difference in price and installing a solar power system to run it. In fact, that's just what I did. The solar also powers everything else when off the grid. It also results in opening up new areas to camp, not dependent on a campground receptacle.
Water damage is the sometimes hidden thing to avoid. It can wreck the framing within the walls and will appear later after some use. It can also ruin the floor and that can be problematic to repair. It sounds like you're tool conversant so shouldn't fear repair work. You'll have to weigh the risk of repair over savings.