Stucco? As in mud? Holy cow! Time capsule, maybe? Did you crack it open to make sure there wasn't any foreign material inside?
I'd say you got lucky to find one at GW. If it doesn't work, you're only out $10 ..., well, and maybe the cost of your replacement power supply.
Yeah thats the stuff, I just figured it had been lying in someones garage for a really long time, because I have no clue how else those two things come in contact. :/
I tried opening it, but thought I might brake the system because of those front screws behind the label. I did manage to shake out a candy heart(that was probably older than I am) that was rattling inside from the system by prying a little though!