An Art Deco zircon and diamond wristwatch

An unusual Art Deco zircon and diamond wristwatch, 1920s, the rectangular silvered dial with blued steel hands, within a geometric border of single-cut diamonds, to three graduated links set with circular-cut blue zircons and single-cut diamonds, the later back section of rope chain, mounted in platinum and white gold, dial 1.4 x 1.0cm, bracelet length 15.5cm, manual winding movement, interior of case back stamped PLATINUM, case back numbered 2750