In the June issue of “The Cadenza” it notes that EN Guckert, of Toledo, Ohio is the owner of the Union Music Co, “ a concern which manufacturers the ‘Duplex” banjos and publishes chord books for stringed instruments.

Guckert wrote and published a chord book in 19191 and 2 years later this was followed by a tenor-banjo chord method, but it is doubtful when he actually manufactured instruments.