Well, I'd say you probably bought a load of junk there. The Compaq is water damaged so it's likely trash, so all you're left with is a NEC base which you don't know the specs of. Even assuming that it's in working condition and has decent specs, by the time you buy the RAM, HDD, WiFi card, CD drive, keyboard, power button, hinges cover, ram cover, HDD bracket, HDD cover, WiFi Card Cover, LCD, and upper housing there is no way you'll come out ahead. That's of course, also assuming that you can find all of these pieces which is unlikely for an off brand like NEC.
Now I've repaired my fair share of laptops, so maybe I can give you a few pointers. First of all, the most important thing for you to do when buying a broken laptop is be certain that the motherboard works. Replacement motherboards can often cost more than what the laptop is worth for resell, so usually the only reason to by a laptop with a broken motherboard would be to use the parts in another laptop. There are some exceptions to this, and occasionally you can find a decent deal on a working replacement mobo on eBay, but this is not something you should count on.
Nextly, stick with name brands. That pretty much narrows it down to HP, Dell, Compaq, Sony, Toshiba, Gateway, ASUS, and Acer. Other brands such as Samsung, Lenovo, Fujitsu etc are still good brands, but spare parts will be harder to find so if you'll want to make sure that you can find them and they are affordable before making the purchase. Completely avoid off brands.
Finally, calculate the repair cost before purchasing. Keep in mind all of the things you'll need to get it functioning. Batteries in particular are important to keep in mind, because a laptop without a good battery has a greatly reduced resell value, but replacement batteries can be quite expensive. Chargers, however, are usually cheap ($10-$20), assuming you're willing to wait the 2 weeks or more it will take to get a knockoff from China.
