I dunno, does david cain strike you as old money? I don't think so...At the most he could be the bastard child of old money. And like jlbarnett said, be of a branch of the Kanes that changed the spelling of their name.
My dad did that with our name actually, and my dad was completely self made (had to be since his old man died before recognizing him as his son and his dad's family rejected him cuz of his dark skin). My dad grew up to be a carpenter and was responsible for building chruches in the city he grew up.

So...there's an idea!