From the April 1955 Women's Home Companion, an article featuring Grace Kelly and how she is able to 'travel light'.

This is an ensemble, with a travel coat and suit, herringbone tweed, arrow straight, over a yarn-dyed worsted suit with easy skirt. Both from Ben Zuckerman. Miss Kelly will board the plane in those so it is not necessary to weigh them (as this article was giving hints on how to pack so as to avoid going over the 66 pound limit for international flights). The coat goes over everything in the wardrobe except an evening dress.

Ben Zuckerman was a favorite of Grace Kelly, she wore an ensemble by him when she arrived in Monaco to marry her prince. She also wore a suit from Zuckerman when she left New York to sail to Monaco and she also purchased a beige coat to wear during the week running up to her marriage.

Princess Grace was not the only royal fan of Ben Zuckerman. In 1964 the Duchess of Windsor attended a charity fashion show where a number of designers were showing their latest wares, including Mollie Parnis, Bill Blass, Pauline Trigere, Jerry Silverman and Ben Zuckerman. When Zuckerman sent out a lovely white cotton brocade evening suit, double breasted with brass buttons, the Duchess cried out 'That is a lovely dress!'.