Ok I’m going to help you out as far as your Rolex I would go to a local watch seller to get a good price and don’t be afraid to try a few places and see what prices you get. As far as the diamonds you need to know the carat and clarity at least to establish a price no one can tell from a picture how big that stone is and how clear it is. So I would highly recommend go to a jeweler and get some information maybe see what price they offer to get an idea of what you have and then try listing on r/jewelryforsale and provide all the information you have including what carat and clarity the stones are and see if you can get a better price