Art Deco Ring In Platinum And Diamonds

Important platinum ring.
It is octagonal in shape.
It features three main old-cut diamonds:
the central one measuring 1.27 carats, color I.
the other two measuring 0.70 carats each, estimated color H.
All three stones are cushion-cut, with a good thickness.
The rim and shoulders are set with rose-cut diamonds.
It has a pretty openwork basket with an "S" motif.
Weight: 7.1 g.
Ring size: 50, adjustable.
French work, circa 1920.