Art Nouveau early 20th century diamond and pearl brooch

Art Nouveau early 20th century diamond and pearl brooch, the openwork scroll motif full set with old eight cut and rose cut diamonds, four oval cream pearl pendant drops, the largest pearl measuring approx 3.7mm x 3.9mm, pavé settings with millegrain detailing, detachable brooch fittings (hinged pin and simple loop), later safety chain, unmarked yellow metal and silver, dimensions approx 3cm x 2.5cm, weight approx 4.6g, in fitted leather covered velvet lined Goldsmith & Silversmiths box, white metal chain with tongue and box clasp concealed within the box (missing pendant attachment)