This Sinuous Chair was designed by Noelle Antignano. It has a simple metal frame that is filled with lushy upholstery rolls weaved through it. A bit like Eleonore Nalet‘s Serpentine Chair. See also this post.
There is a design auction at Phillips in NYC on December 13, 2016. Lot 110 is this Gio Ponti 489 armchair for Cassina. Estimated $15,000 – 20,000 for the two.
Update: Sold for $37,500
Lady Lounge chairs by Marco Zanuso, manufactured by Arflex. Winner of the Gold Medal prize at the 1951 ‘IX Triennale’ in Milano. Newly upholstered with deep blue velvet upholstery.
Sold by 1stdibs dealer Decade in Milan where I found it.