NEW YORK — The life of Raymond C. Yard (1898-1964) demonstrates the power of a heavy-hitting early endorsement. Born to a railroad conductor and a stay-at-home mother, he began his career in the jewelry trade as a door attendant and errand boy for Marcus & Co at age 13, one of the top jewelry firms in New York City. Yard went from earning three dollars a week to becoming one of its top salesmen. In 1922, at the urging of one of Marcus’ most affluent patrons, John D. Rockefeller, Jr., he decided to hang his own shingle on Manhattan’s iconic Fifth Avenue. Rockefeller promised to bring Yard business and he kept his word, not only having the young man design jewelry for his wedding but recommending him to his friends. The jeweler was soon courted by movie stars and high society clients, many of whom commissioned statement pieces from him.