There do seem to be people selling 7d mark ii cmos sensors for ~$300, while a new body would cost ~$1100.

Someone posted a video of replacing the sensor on the old 7d (https://www.youtube.com/watch?v=udonzfGdW0Y)

Seems it eventually worked for him, after several attempts to adjust the position to get correct focus, but if you read the comments on the video there are many people who've messed up their camera trying to do this.

Might be fun to try though.

They blog a lot about their repairs process in general. It's primarily mechanical damage to lenses they appear to normally deal in - the focusing rings, aperture mechanisms or realigning optical elements dislodged by drops and so on. An embedded CCD/CMOS sensor is probably a full logic board replacement I'd assume, as opposed to some kind of sensor only replacement, given it's almost always soldered on.

I know about 12 years ago I blew the firewire connection on my video camera (Canon xm2), and to fix it they would have to replace the full board.

So I feel like they don't make them repairable.