Vintage sterling rose brooch

In nice condition and kept in a clean smoke free home. Marked 800 and tested sterling as shown in photos. There is a small orange discoloration above the 800 on the back. It doesn’t affect the wear. I did try to remove it with sterling cleaner and baking soda and vinegar. Not sure what caused it. Pretty sterling rose brooch estimate date 1950’s. Researching I found it valued $100-$200. 3 1/2” X 1 1/2” beautiful detail throughout, sterling silver with black detail on leaves.