I doubt if anyone thought it was an original idea to have the extra buttons, my only curiosity is the configuration of the notes of the extra buttons. It is not simply adding notes, but a little thought into whether push or pull, or both, and which note in what location based on fingering. Been fretting over this a while. Probably a lot of combinations that would work
Nice to see what is old is new again. I used to see a lot of German two row button accordions with the extra buttons as shown on Steves accordion. However please note that there was a reason that the old bass box was discarded and the bass buttons were put on the face of the bass side frame. That made them much eaiser to play and what I think is a nicer looking accordion. I once had a book on the history of Hohner accordions which had pics. of many of those old accordions and also showed the evolution to the newer two row German accordions with the extra buttons in the 1940's. Fingering was not at all what cajuns would used but all that can be changed.