Interior designer Marie Flanigan channeled her inner mix-master with a layered blend of pieces old, new and somewhere in-between for the home’s living room. An oak-framed armchair in the living room “could be from the 1940s or now,” the designer explains. She paired the time-defying piece with a sleek oak bench with a woven seat, a coffee table-turned-toy-storage chest upholstered in waxed leather, and a newly re-covered sofa the couple bought as newlyweds.