Based on your post, this rear sounds like it is in god shape. The only question I have is the last few photos show some pitting on the ring gear. Do you have a better photo of this?
I have other photos, but of the same quality as what is posted here. I have to admit, all I see in the photos are the spots of rust that wouldn't wash away without scrubbing. Could you be specific about where you see the pits and I can look for a better photo. I think the rust debris and my poor photography might be what appears to be pitting. I did not scrub off the rust, so there may be pitting underneath, but I did not notice much, if anything wrong with the surface of the ring gear. But that doesn't mean it's not there.
