Siam Sterling Silver Niello Large Openwork Brooch

Siam sterling silver nielloware. Ramasoon and Mekkala. Open work center. Marked Siam Sterling. 14 grams, large heavy pin. Vintage. I have thousands of pieces to list. I collected for decades. All pieces ship in a box properly packed. I wish I could polish it all but I can't. Almost all Siam Sterling is .925 it may be marked or not.