Looks good. I guess the difference between that and an 'ordinary' chromatic is that you can combine any keys - G/D for instance to play along with English melodeon styles?

Difference between it and my dreamt up one though is the Power's one still has a button and single row of holes. With my dreamt up one there was no button and two rows of holes so, for instance, you could accompany yourself on guitar. You would lose speed but gain flexibility. I think!

DtG