I noticed that on one of my trench watches I have something that looks like black paint around the lugs and behind the clasps. You can see in the close ups that this is not silver tarnish.
I then happened to see a black painted trench watch in a vintage watch shop (sorry for the bad photo - too much contrast. No name on the enamel dial). So my question is: were some trench watches originally painted black?
It is a silver Omega from about 1915 (movement number 4 862 713).