1900s Omega Hunter Pocket Watch: ID and Discussion

Dear all, i have received this Omega hunter pocket watch as a gift from my great grandfather. The only piece of information i have is that it comes from Switzerland and the number 3833253 is engraved on the case. I don't even know if it's gold plated or in gold.

I would like to have as much information as possible regarding this watch, what is the best way to restore it and maintain it and the expected market value. I am not looking at selling it i want to keep it but i would like to understand it's value.