I'd go for it- just because they're sitting out in the rain doesn't mean anything except wet cases. Most of the stuff inside is probably fine if they were working when dumped. You could probably salvage the floppy drives for a few bucks each, CD-ROM drives for less than 10 bucks, 16MB of RAM for probably 10 bucks, CPUs for 10 bucks... those are multiple 10 buck component computers! You could make enough to fill a monthly beer allowance! 😀