A large, rectangular copper alloy mount, pierced by small rivet holes along its two longer edges. The upper edge has rivet holes in each corner and a row of three small holes close to one edge. The lower edge has been cut and a part has been folded back; it is surrounded by three rivet holes. Further towards the edge lie four further holes, arranged in a tight bunch. A curved strip of copper alloy wire remains in one rivet hole, at the corner of the lower edge.