Antique flower ring in gold, platinum and diamonds featuring a floral motif

Ring in 18k (750°/°°) gold, platinum and diamonds drawing a floral motif composed of a main line composed of five diamonds, one of which is larger, and two symmetrical side lines drawing flower petals composed of smaller diamonds.
The largest diamond is oval and old cut and weighs approximately 0.80ct. The total weight of the diamonds on the ring is estimated at approximately 2.5 cts.
French work from the 1950s/1960s
Eagle head hallmark for 18 carat gold and dog head hallmark for platinum

Dimensions of the main stone 5.75 x 6.26 x 3mm (the depth is estimated and could not be taken precisely because it is not accessible)
Finger size: 57
Gross weight: 6.84 grams