The dedication plate may be translated:" At the 25 year anniversary of service on October 15, 1926, dedicated by the leading officials of the Duerkopp factories plc." At that time Duerkopp in Bielefeld was a leading German bicycle and sewing machine manufacturer. The company still exists as a maker of industrial sewing machines, see: http://www.duerkopp-adler.com/de/index.html