String shelf in wood and black metal

"billa" string type shelf made in sweden 1960s in wood and black metal. Presence of labels authenticating their origin. In excellent condition despite its great age. Materials: teak veneer on pine (boards), black metal (structures) and plastic (beads system for installing the boards). The system of this shelf is quite ingenious: using diamond-shaped beads, hooks screwed onto the boards fit into them. This system makes this string type shelf modular to the nearest centimeter. Normal wear marks (see photos). Only one bead is slightly worn but this does not prevent its use (see photo). Not all the hooks are as pitted as the one I took a photo of. Additional dimensions: total height available to install the shelves: 62 cm.