it is a little hard to see but i looks like the ring gear has rust where it interfaces with the pinion. you can put some marker on it and check the pattern. if the pattern looks good and is not hitting the rust area you should be fine. if it is hitting the pitted area and it is not to deep i would probably run it. i would want to keep an eye on the oil though. check it here and there for shiny sparkly stuff in the oil.