Historical Commission and Historical Society members gathered at the Swampscott Lilac Garden on Monument Avenue Wednesday afternoon to dedicate the new Deborah Moody Lilac Garden interactive sign to the late Swampscott historian Louie Gallo.Surrounded by more than 67 different varieties of vibrant lilac trees, a new sign tells two different stories one of a trailblazing woman from colonial Swampscott , and the other about the historian who unearthed her story.