“Chairs were made by Ercol Furniture. Ercol, Gamper Martino and Wallpaper worked closely together to achieve this arch.”
-Ercol Furniture Rep. (E.Tadros).
Thank you for the information and the inspiration!

Original Post (below)
Chairs designed by Gamper Martino, project “Chair Arch” commissioned by Wallpaper*. Exhibited in London.