Well, without looking that closely, the C64 might be salvageable. Would probably be easier for CWC to hock it off "as-is" on ebay, than going through the hassle of getting it fixed, unless he wants to keep it.
EDIT: Well, by the looks of it, he hasn't opened it up. The thing with electronics this old is that they might go off when thrown into the junk pile. The RF modulator's rust pretty much nonissue(I mean, he has the proper monitor for video after all, nobody uses RF outputs anymore), and the plastic seems to be in condition you could restore it in an afternoon. I think the unit itself needs through look before any judgement is made, the rust has probably gotten to the RF shield inside, there will probably be dust etc, the chips could also need reseating or replacing. Oh yeah, and he'll probably run it with OG power supply, which is ticking time bomb too in itself. In right hands, it might be fun project.