general opinion about repairability of MacBook 2007

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.

Fixing water damage on a MacBook is rather impossible, assuming that the previous owner most likely shorted the logic board by failing to cut power to it. The same thing happened to mine a year ago (R.I.P. Logic Board). Luckily Apple was feeling generous and repaired it for free, but the cost of the new parts would have been upwards of 700 dollars. However, fixing one that is broken in other ways could be a lot more doable, inexpensive, and fun!

I really don't like liquid damaged machines. In my opinion they're money pits. Better to use your knowledge gained here and look for one on eBay that has symptoms that you know how to fix. If there have been no bids on this type of machine I will write them and tell them how to fix it. If it already has bids, then doing that does no good and I might as well get it for myself. I bought three of the 17" 1.83 GHz iMac that had screen recalls on them (Apple fixed them all for me). I've bought three MacBook Pros with the Nvidia issue (Apple fixed them all for me, free). Even if Apple doesn't come through, you know what the problem is and the costs to repair. Some people just don't want to mess with a machine with a bad hard drive or cracked screen or even a bad power adapter. You know where to get answers and parts. But I would never buy one without a pretty certain knowledge that I could fix it.

The A1181 is a very reliable and repairable laptop. Lots of parts out there for them. You can get them for a good price if you pay attention. As previously mentioned the test equipment for doing chip level repair can be costly. Not all repairs require that type of work. I've purchased an A1181 with the same specs you mention functioning properly with a broken LCD for $127 including shipping. Ive purchased perfectly good used LCDs for this MacBook for as low as $50 including shipping.