CBS owns KCBS, so there wouldn't be any problem there. Perhaps there's some kind of royalty problem running TV advertising on the radio. In that case, KCBS could insert weather reports or radio ads during the commercial breaks, but perhaps that's too much work.
I know you can stream 60 Minutes - divided into the individual story segments on cbsnew.com. You can also listen to it on that old fashioned radio thing, or watch it on TV where it's a more complete experience.