This will be an interesting auction to watch for Jack Swigert's gold Rolex GMT found here.

The bezel can probably be explained between the WSS picture below and how it's being sold today. It looks to be a well worn watch or had an unfortunate encounter with an aggressive polishing wheel.

 

Indeed, my first thought was about the WSS portrait of Apollo 13 CMP Jack Swigert

 

I don't know much about gold watches. So the appearance is more likely the result of daily wear over the years and the soft nature of gold?

EDIT - Found the answers to my question about the wear on gold watches.