Antique diamond cluster ring with a central old cut diamond

Antique diamond cluster ring with a central old cut diamond estimated to weigh approximately 1.5-1.7cts, surrounded by a border of eleven further old cut diamonds in platinum setting with pierced gallery on plain shank. Estimated total diamond weight approximately 3.2cts. Ring size N. The central stone measures approximately 7.8mm-8.0mm diameter x 4.2mm deep and estimated to weigh approximately 1.5-1.7cts, it is a lively bright old cut diamond, estimated colour I/J, eye-visible inclusions, some surface reaching, estimated clarity I3. The eleven smaller diamonds are all well-matched lively bright stones and estimated I/J colour and SI1-I1 clarity. The diameter of the cluster is approximately 4.6 - 4.8mm. The setting and shank appears to be platinum and/or 18ct white gold, not hallmarked, good condition commensurate with age. Weighs approximately 4.0grams.