This is an accordion feature, and I know not every group has access to accordion or additionally one that improvises on a level to carry a feature such as this. So, there might be alternatives that I’ve yet to hear. I think this could possibly be a beautiful piano or vibes feature, or maybe even violin or soprano sax (if someone can cover the other reed part). Think creatively, knowing the musicians you have available.
The doubles on this are not technically difficult, but it is important they have a good sound. 5 reeds, 4 trumpets (trpt 1&3 play flügel, 2 needs bucket, 4 needs cup), 3 trombones (1 needs cup, 2 needs straight, 3 needs bucket), 1 bass trombone (bucket), accordion, guitar (with electronic almost angelic effects), piano, bass, drums (brushes).