Reading this IG post I am wondering how many necklaces formerly in queen Marie Antoinette of France's collection belonged to Barbara W. Hutton:

https://www.instagram.com/p/CWJ6ds-orxZ/

Maybe she had a couple of necklaces from Marie Antoinette? Or maybe the sellers claimed this illustrious provenance in order to get higher bids? Barbara Hutton's collection, as seen in the pictures, was plenty of pearls, so I doubt all of them had the same provenance