When I finally opened it up today, I found a Ryobi HP62 6.0 volt cordless drill inside. It looked absolutely brand new. I mean, really, it looks as if it has never been used at all. All the bits save one were there. I figured, "let's charge it up." That's when I noticed that the wall wart in the drill case was from an AT&T answering machine or cordless phone. The AT&T charger has a 9vac output. Hmmmm, I wonder if that's why the drill got thrown out.
After some searching, I found a Canon 6 vdc, 300 ma charger, probably from an inkjet printer, that charges the battery pack, but not any too fast.
The proper charger for the Ryobi is a Ryobi-Ridgid part 7221001. I don't know what its output voltage or current is. If anyone has one of these chargers lying around, I'd like to know the specs on it. I'm sure that in my massive collection of wall warts I have one that's close enough.