When teaching the EC, I have students that play all makes and levels of instruments. From Wheatstone to Wren, From 30 button to 64 buttons, and Baritone, Tenor/Treble, and Treble ranges.
I often use Violin Etudes for students to help with fingering and phrasing and notation. However, not all English Concertinas have the same keyboards. Jackie keyboards have 30 buttons and 48 button treble EC keyboard adds an additional octave above the Jackie. Most Etude studies have notation above the range of Jackie. Fingering of the Jackie adds an additional variable.
Using the software Musescore, I transcribe the Etude two different ways. I will usually lower the out of range note of the Jackie down by a third but keeping the same notation.
Here is a line from Etude #29 from Franz Wohlfahrt's Violin Studies Book II. First one is for a 48 button EC and second is how modified for the Jackie. The Etude is in the Key of C. The High D in the third measure is changed to a B to accommodate the range of the Jackie.
For a 48 Button Treble EC:
For the Jackie EC:
This particular etude is wonderful for learning techniques for fingering, phrasing, and playing detached and legato.
Tenor/Treble ECs may add some additional changes to an etude, but that's for another time.