Did this with a BlackBook
Got a black Macbook 2,1 for €20 a couple of years ago, fitted it with a new battery (another €20 from Aliexpress) and Librebooted it (it's one of the few machines that can be modified entirely in software). Currently running Trisquel Lite to keep it fully "libre". Lent it to my daughter as an emergency PC for university, though she complained about the weight...
Of course, as it's libre, there are no drivers for the webcam (a plus in my book) but you can easily attach one via USB if necessary.
The only problem is that it gets hot quite quickly - some people have drilled holes in the underside in front of the internal fan to improve ventilation, but I haven't been that brave yet.