MOVIN’ ON UP: Michael C. Fina, the family-owned and operated retailer known for its comprehensive collection of diamond engagement rings and wedding bands, and large tableware offering, has a new address. After 15 years at 545 Fifth Ave. at 45th Street, the retailer has relocated to 500 Park Ave., an elegant office building with a prestigious condominium tower, between 58th and 59th Streets. The new Michael C. Fina store is smaller than the former one, with about 1,000 square feet on the ground floor and 5,600 square feet of selling space on the lower level. It has 60 feet of frontage. Michael C. Fina’s Web business is growing, so it didn’t need quite as much physical space. “The move to 59th Street exposes Michael C. Fina to the demographics of upscale residents and office workers,” said Stephen Stephanou, a principal of Crown Retail Services, who represented the landlord. Michael C. Fina was represented by Gene Spiegelman, executive vice president of Cushman & Wakefield. The retailer was founded in 1935 at 580 Fifth Avenue and 47th Street. Michael C. Fina had hoped to open the doors to its new store in time for Valentine’s Day, but construction wasn’t finished. However, the company can feel secure in the knowledge that it’s been helping couples get engaged and married for the last 78 years.