I would have made violin strings from my cat if she were to ever do that. Get rid of that feline.....sounds like it's not Mac friendly...
I don't remember if those PowerBooks have the keys that mount on top of a rather small-and-difficult-to-remount folding mechanism. Most PC laptops have them, but I'm not sure if the 'Books have them. If so, you can attempt to place the keys back on, but it's going to be an exercise in patience for you. I had to do this recently with an HP laptop recently and some older Dell laptops in the past, and it does take some patience but it can be done. Good luck.
• Apple iMac G5 17" (2 GHz G5) - Mac OS X 10.5.8/Ubuntu 10.04
• Asus Eee PC 901 (1.6 GHz Atom N270) - Fedora 13
• Apple Macintosh Quadra 650 (33 MHz MC68040) - Mac OS 8.1
• "JHVH-1" (2 GHz AMD Athlon XP 2400+) - Slackware 13.1