In 1874 he was associated with David H. Dunham, of Dunham &amp; Sons, with whom he patented improvements in iron frames and wrestplank bridges, and in 1877 the Mendelssohn Piano Company advertised their latest trichord squares used "Mathushek's new Duplex Overstrung Scale, the greatest improvement in the history of Piano making," and claimed to have received unanimous recommendation for the highest awards at the Centennial Exhibition in 1876, where the Mathushek Piano Manufacturing Co. had also exhibited pianos.