A Grade 345 Elgin, With Some Ugly Corrosion

This watch had just a touch of actual rust visible on one of the case screws, but inside it was another story.

 As is often the case, it's not as bad as it looks.  Gold, brass and nickle plated parts can look rusty and stained, but they actually don't rust at all, and clean up quite well.

The movement is a grade 345 Elgin.  It's a 12 size, 17 jewel, product, made about 1924.