So I'm rebuilding my 13B for my 04 RX8 and when I was cleaning the housing in my parts washer I noticed some chrome chip on the top of the housing, my question is should I replace it, could I machine it or just leave it alone and proceed with the rebuild also the rotors had a ton of carbon buildup on them, not sure if that's normal or I should be concerned, I managed to clean all the buildup off though

 

That's some serious chatter marks and chrome peeling. If you want any compression you should replace the housings....