Just a thought (from someone who doesn't know pocket watches): I would have expected to see a brass case on an old watch. Instead it's corroding like some lesser material. But for all I know it could have been a stop watch.
Yours appears to be a stem-wind (aka stem-set) movement, which started to become popular in the late 1850s. The invention of stem-wind movement did away with watch keys. The stem-wind/stem-set movement is the most common type among both vintage and modern pocket watches. So, the moral of my story is that your watch dates after the late 1850s to gosh only knows when, and without serial numbers or case numbers, and not knowing the manufacturer, it's impossible to date your relic. Very cool relic though! I like it!
Cool find..
I don't think it will withstand much cleaning.
I would just give it a light brushing, soak it in rubbing alcohol for a week to pull the water out, let it dry well and coat it with clear lacquer.
Neat find congrats