I bought them from Bill, a Dutch guy who used to sell designer furniture in Antwerp, where I live. He was a big guy who had a shop in the Kloosterstraat. Not so long ago I ran across him in the Bleekhofstraat.
Mari belongs to the generation of Italian designers celebrated by the MoMA in their exhibition Italy: The New Domestic Landscape (1972) which had this to say of him in their catalog:
“Enzo Mari was born in 1932 and works in Milan. Beside his extensive activity as a designer, since 1952 he has devoted himself intensively to theoretical research, especially on the psychology of vision, systems of perception and the methodology of design.”
Arte made this portrait of him: