[Stephen]

Yes indeed, I was talking about Jarry’s mini accordina named “baby accordina”.
But 2 octaves (24+1 button) is not enough for me, I would need 2,5 octaves (from g4 to c7, the highest note of a diatonic mouth harp). Many tunes and songs (eg in the key of C) start from low g4 with a jump to the tonic note, c5.
With 30 buttons I can play all the tunes I want, without having to transpose to another key.

The accordina though is not easy to make, you have to drill the holes in solid wood.
Looking at photos of the inside of the Borel piano Clavietta or the old (green) Hohner Soprano melodica action, these are easier to make. The (old) green Hohner soprano melodica had all the keys mounted on 1 single metal bar, and the reeds lay very close to the push keys. That would be a bit easier to make.