I did an acid test on the watch and it tested 10K. So I then took some 22K acid and poured it on the rust and it helped quite a bit, but I think I better go back to the lower test acid to keep from erasing the gold. I have it in olive oil now but that has never done anything except waste olive oil. I might just put some acetone on it a few times, liquid wrench, and anything else I can think of to dissolve some of it. It has a back that opens up and a front that opens. I want to open the back to see if there are any markings, etc.. quite often on the center around the edge there are serial numbers, makers mark, etc., and if you open the front you can see the writing.