1930s brass "up and down" suspension

White porcelain and brass-plated adjustable lampshade. (pulleys and counterweight). White opal glass shade with a clear, folded edge. + 1 white porcelain switch. All fittings are brass. Socket, shade support, pulleys, and counterweight. 25 cm diameter. Height adjustable, weighted. 2 pulleys. Brass-colored wiring completely replaced. Just plug it in...