For comparison see:
L. Dosi Delfini, The Furniture Collection Stedelijk Museum Amsterdam, Rotterdam, 2004, p. 304, no. 471 for an identical Beugelstoel
The present Beugelstoel is the second known example. An identical chair is in the collection of the Stedelijk Museum in Amsterdam (inv.no. KNA 6660). It is a version of Beugelstoel 2, a model with a higher backrest.
The use of fibreboard instead of plywood as well as the solid tubular steel frame indicate that the present chair is an early piece.