I had my Seamaster Cosmic 2000 (166.128) serviced last year.

However, I haven't inspected the watch till recently and I noticed these markings on the inner bezel.

Is this corrosion of the actual inner bezel metal? Could this sort of thing be buffed out or do I need a new inner bezel (they're still available). After looking more closely, I see they're all around the ring. It bugs me as it's the only blemish on the watch that's noticeable.

Finally, can someone recommend a watchmaker that has the proper tools and experience with opening a Seamaster Cosmic 2000 case? My regular guy is still booked like crazy.

Thanks for your help!