Industrial tubular metal stick sitting round in wood

Charming stool, perhaps from workshop or school, with a circular wooden seat and a tubular metal footing in white ecru (not original). This same painting also covered the seat that I stripped and sanded to find the original wood, consisting of several layers of fine wood glued, light tint. I also spent a very thin layer of colorless matte varnish, just to protect the wood. Given the strength of the structure, the significant thickness of the metal, I think it dates back to before the 80s, but since the seat is not solid wood, it must be after the 50s... So date back to the 60s or 70s. It is still very solid and stable (not wobbly), but does not hide its age: the 4 rubber skates are present and functional, just a little worn, the paint on the structure presents some spots, scratches and gaps. The wood has stains and stripes and some leftover paint and an old varnish. This stool is 46 cm tall, the seat has a diameter of 32 cm. The encroachment is a square of 31 cm side. It weighs 2.7 kg.