Does it smell?
Apparently a lot of iBooks smell like sweat, something to do with the glue used in the keyboard: https://lowendmac.com/2006/a-stinky-old-ibook-that-smells-like-sweat/
I've got a 2007 BlackBook (MacBook 2,1) which is about the easiest machine to install Libreboot on (all done in software), now running Trisquel Lite.