My great grandfather's Koch Harmonica button accordion from Germany--possibly close to 100 years old | Button accordion, Accordion instrument, Hammered dulcimer
Accordéon Koch harmonica vintage des années 20 - Etsy France
KOCH STAHLTONE 12 BASS BUTTON ACCORDION C/F/G 1950-1960 wood white and red | Reverb France
1920's Koch button accordion | Collectors Weekly
KOCH STAHLTONE 12 BASS BUTTON ACCORDION C/F/G 1950-1960 wood white and red | Reverb France