Avid collector, historian and designer Didier Ludot is the last word on vintage haute couture in Europe. Designers depend on him for inspiration, museums for exhibition pieces and high society dames to pass on their couture castoffs.

And with good reason. Since 1975, Ludot has been collecting and selling fashion and jewelry in the gardens of the Palais Royal. He also alleges to be unlike any other—which actually holds some weight. Museum-worthy pieces of the past century are sourced exclusively from grand French haute couture maisons (from Hubert Givenchy to Reveillon furs), with the exception of a few Americans (Valentina, Charles James, and Mainbocher). Fashion know-it-alls will be ecstatic to find significant looks such as Christian Dior’s post-WWII “New Look” silhouette and Cristobal Balenciaga’s sculptural works circa 1960.

The only thing missing: a 1965 YSL Mondrian dress. But surely a fashion dame will give hers a new life in the Palais Royal.