Hugh,
Following your posts on the Chromatic "B-Griff" Keyboard I thought that you may be interested in these videos by Karène Neuville.
Karène Neuville 16 ans - Medley à La Chaux
Karène Neuville 2019 - Medley à Renaison
The black accordion that she plays is similar to the one I had. On the first video she has the overlay on a Ketron keyboard (Time 3:17). She also uses the Ketron as an amplifier, plugging the accordion into some port on the back of the keyboard.
Lots of her on YouTube. Love her playing.
Den