There are some missing stones, I counted 7, hopefully didn't miss any others, and a few that have darkened a bit. Overall appearance is still very nice for a piece of this age, and it is hard to find these with all of the pieces together. The frame is marked Coro Duette and has patent number on it.
The item "Vtg Coro Duette Pin Brooch Dress Clips Trembler Rhinestones Enamel" is in sale since Thursday, January 2, 2020. This item is in the category "Jewelry & Watches\Vintage & Antique Jewelry\Costume\Designer, Signed\Pins, Brooches". The seller is "pattym0112" and is located in Gaylord, Michigan. This item can be shipped to United States.