And then, then I find Mid Mod Design, a Dutch collector and seller of mid 20ieth century modern furniture, who had this very interesting chair for sale.
The chair was designed by Amsterdam based Dutch artist John Striegel in 1983. Originally he planned to make 100 of them, but he found out that was too time consuming. Eventually he made 18 only. Most of them went to family, some were sold to the UK. As a consequence they seldom will be available for sale.
The chair is a sculpture and a homage to the Steltman chair by Gerrit Thomas Rieveld. It was was made of heavy massive beech wood and lacquered in white. Signed with tag on the bottom: Striegel & Barkey (Designer/manufacturer), 014 -100 (production number), 16-06-83 (date).