Viennese Belle Époque Gold and Platinum Cluster Ring with a Round Rose Cut Diamond Center

Period and details: Belle Époque era with a restored center bezel; the ring hails from Vienna, under the Austro-Hungarian Monarchy. The stamps (noted below) were in use from 1867 - 1922, but we date this piece to the early 1900s.  Materials: 14K gold; platinum; diamonds Stamps: within a sort of elongated hexagonal frame, there's “A”, the head of a left-facing greyhound, and “4”; there’s a second “A” stamp (presumably the maker’s mark, or perhaps it's a restatement of the Vienna Assay Office) within an impressed box with rounded corners Size: 6 3/4 (free sizing where sizing is possible—contact us for more info) Diamonds: approx. 2.57 ctw.; Accent diamonds graded in their mounting by a GIA GD—weights and grades are approximate      Center: a 1.02 carat Round Rose Cut diamond (GIA assessed as Round Modified Brilliant; J color; SI2 clarity)      Primary accents: 1.40 ctw., est.; eleven Old European Cut diamonds around the center with approx. H-I color and ranging VS to I clarity (approx. S