The treble side also has similar tuning issues. It probably dates from mid 20th century.
Hohner Erica DG Melodeon – Diatonic Accordion in black celluloid
DG Hohner Club II Melodeon Diatonic Button Accordion 2 Voice MM
Vintage Melodeon Hohner Pokerwork Laurel Leaf B/Es Accordion
Vintage Hohner 1 Row Pokerwork Melodeon in the key of C
DG Hohner Pokerwork Melodeon 3rd button start 2 voice Made in Germany
Hohner Single One Row Melodeon C HA-114C
