Wow, you still have that machine? Yes, and it is the only working example I know of. It's here . As to "eye of the beholder", I'm not sure which features one might include in a "real PC" that the MCM didn't have? Or the Compucolor II, which started orders in December 1976, and s...

There are various definitions of "personal computer" so it is sort of in the "eye of the beholder". As I read your definition, I thought of the MCM/70 as well, to be honest. Many people don't know about this computer and how early it was but I am fortunate enough to own one.