A late 19th/early 20th century 18ct gold and platinum mounted diamond ring set with five graduated

A late 19th/early 20th century 18ct gold and platinum mounted diamond ring set with five graduated old cut stones, the central diamond approx 0.72ct, total approx 2.5ct, hallmarked '18CT PT', size Q, approx 4.3g. CONDITION REPORT One diamond 5.50mm x 5.00mm x 3.74mm, estimated weight 0.72ct, clarity VS, colour J/K. Next diamond 5.30mm x 4.90mm x 3.38mm, estimated weight 0.61ct, clarity SI, colour J/K. Next diamond 4.10mm x 4.00mm x 2.81mm, estimated weight 0.32ct. Next diamond 5.10mm x 4.70mm x 2.96mm, estimated weight 0.49ct. Next diamond 4.10mm x 3.90mm x 3.21mm, estimated weight 0.36ct, clarity I1, colour J/K. Condition good.