I think just like on Amiga PPC boards, the PPC on a Mac is surface mount. Probably not easy to scavenge... and even if you did, even harder to re-use.
I have an old PowerMac 7200 I saved from a junkbin. Not much of use on them. Some older Macs had SCSI CD ROM drives and SCSI HDs to steal and re-use. Barring that, not much to scavenge, really. The RAM and floppy drives aren't compatible with too much. At least not on the pre-G3 PowerMacs.
Best bet, if you don't want to trash it outright... run PPC linux. If you can add an extra NIC, it would make a nice firewall, or something.