Tank ring in yellow gold, platinum and diamonds

Tank ring, 1940s, in 750/1000e (18k) yellow gold and platinum, set with rose-cut diamonds.
Diamonds: 2 central roses of approximately 3.8 mm and 4 roses of approximately 1.8 mm
Condition: the ring has just been polished, the roses have micro-shocks and scratches, it has not undergone any restoration at the stone level.
Dimensions: 19 mm / 11 mm
Gross weight: 8.13 gr
Finger size: 54
Hallmarks: the ring has been re-hallmarked: owl for 18k gold
ref.519