Stopped in today at my watchmaker to see haow some of the repairs are going. While there I showed him the wafer thin 100 with the heavy corrosion on the back. He suggested the use of a clear nail polish. It will fill the voids and help prevent furhter damage.
i did explain I had tried some metal filler but, the problem is it dries a dark gray. It would have to the sprayed with a gold paint. but, not sure it worth all the effort and how good it would look anyway.
In this state the watch is clearly lived in and tells a better tale of having provide years of use to its owners!