Bandeau ring in platinum and diamonds

Bandeau ring in platinum (hallmark: dog's head), set in its center with a half-cut diamond, weighing approximately 0.70 carat (estimated color I, estimated clarity SI2), in a shoulder of six round diamonds cut in 8x8 and in the old style, whose total weight is estimated at 0.80 carat. Circa 1920, Art Deco, France. Unidentified master's mark. Condition: very slight micro scratches and deformations on the platinum parts, natural inclusions in the stones, see photos.