Water damage is almost always not fixable (Without tons of testing equipment, plenty of free time, and really good luck) I actually have two PowerBook G4's sitting in my closet with water damage, and I've pretty much given up on them. I've already sold their working parts (Superdrives, LCD assemblies, Ect) because the chance that they'll ever work again (Without a logic board replacement) is pretty low. So to answer part of your question, repairs on water-damaged laptops (and most other complex electronics) are usually not successful. However, if the other parts of the laptop work, you could sell it's parts individually.
