Sarah Faust, president of Faust Harrison Pianos, was recognized Tuesday as the owner of one of Westchester County’s most outstanding family-owned businesses at an awards ceremony in White Plains. The White Plains company, nominated for the award by the Westchester Conservatory of Music, has been restoring and rebuilding “golden era” Steinway pianos for nearly 40 years, when Sarah started the business as a sideline to her career as a concert pianist.