The Merchants Mutual Insurance Company headquarters is located at 250 Main Street in downtown Buffalo. It was built in 1964 by architects James, Meadows & Howard, which originally began as the famed Victorian-era Green & Wicks firm and morphed into this incarnation by 1953. Chuck LaChiusa supplied me with the architects and date of construction and his Buffalo Architecture & History website lists other buildings designed by this firm. The strikingly uniform facade consists of alternating rows of recessed windows and stone panels with larger floor to ceiling windows at street level.
As seen in the photographs below, the first floor level has some unusual heptagonal-shaped metal lighting fixtures. The original signage is also in place although the name of the company has since been shortened to Merchants Insurance Group.