I have had this motor in my shed for over 3 years now and decided to tear it apart. Its from my 83 parts car the chrome on the housings looks good no chattering or grooves just this (flaking??) near the edges of the housing. Heres pictures.

 

For 12a Housings those are definitely usable. Some will say otherwise, but in reality, there are no new 12a housings available so we can't be too picky. My criteria for a usable housing is that they have no chatter or groves and that any chrome flaking be less than 1-2 mm in width and not in the compression area. Looks like your meet all of the above. Rock out!

 

cool thanks alot. I have another parts motor to rip apart and see if those are better. I couldent find any criteria to go by other than no chatering in the compression chamber.