According to the site Musica Viva, Ands. Koch A.G. was a German accordion and harmonica manufacturer in Trossingen, founded by Andreas Koch. In the early part of the 20th century, Ands. Koch A.G. was one of the world’s major manufacturers for these instruments.

It was sometime between 1914-1916 that the company’s name was changed to Koch-Harmonica Werke. Further to that, sometime between 1916-1925, Hohner bought the company out, but allowed it to run somewhat independently until the 1930s. The name plaque on this instrument would date it circa 1914.