Founded in 1948 and now in its third generation, Nikki & Co. Fine Jewelers & Rolex Watches occupies 562 Fifth Avenue in downtown San Diego's Gaslamp Quarter as a GIA-certified diamond and pre-owned Swiss watch specialist. The estate jewelry inventory spans pieces from the late 1880s through mid-century — Victorian brooches, Art Deco cocktail rings, Old European-cut diamond solitaires — curated with the same era-specific material knowledge that distinguishes custom suiting at Art Lewin Bespoke Suits. The pre-owned watch department carries Rolex, Patek Philippe, Audemars Piguet, Cartier, Breitling, and Panerai, with on-site servicing for movement overhauls, crystal replacements, and bracelet refinishing. All loose diamonds are GIA-certified, and the shop builds custom engagement rings around client-selected center stones at wholesale-to-public pricing tiers. Consignment and trade-in services extend to both watches and jewelry, with estate appraisals documented to the standard that carriers like Hultz Insurance accept for high-value personal property riders. Highest-tier watch services include Rolex-caliber movement overhauls, mainspring and escapement replacement, case and bracelet refinishing, and pressure-tested water-resistance recertification to factory specifications.