I don't know how I was unaware that clickykeyboards.com sell a PS/2 to USB adapter converter that I've been looking for without knowing exactly what I was looking for other than the cheap adapters weren't fulfilling my needs.
(Funny aside: the last time Laurel had a friend over for a playdate, the friend commented that we should get a new keyboard because the one on the communal household computer has several keycaps that have had the letters worn off. Maybe I'll buy one of the 84-key Model Ms to replace it.)
Also, for next year's science fair project (since Laurel is still fascinated by fingerprinting), I need to bookmark Crime Scene so I can stock up on supplies. And maybe buy that "Crime Scene - Do Not Cross" lanyard to wear at day camp. Hee.