That's got a great design. Very nice find.
I find it amusing that I am all of a sudden very interested in jewelry appraisal. I never thought I would find myself reading up on that!
FYI: I don't know if this is commonly known or not? If it's confirmed silver, you can quickly and safely remove silver tarnish (oxidation) by using aluminum foil, baking soda and hot water. Lay a piece of aluminum foil (shiny side up) in a bowl and put the silver on top (in contact with the foil), heat a little water to a boil in the microwave, and pour the hot water in the bowl (covering the silver and foil), shake baking soda over it all. It will start to bubble and fizz. Wrap the foil over the silver (increasing the points where the foil is in contact with the silver), and shake it about. The whole mixture produces a light electrochemical reaction that pulls the sulfur and oxidation off of the silver and deposits it onto the foil. It doesn't remove any silver.