Idiots.
1) the only people who would want to tinker with a C64 are geeks.
2) they would want to open it up and work with the original parts.
3) Geeks are smart enough to recognize the difference between a C64 and some crippled state of the art processor.
The C63 was maybe 15” across, 6” deep and a couple inches high. You should be able to fit a mini-ATX motherboard and the other basics in there to make a pretty decent PC.