I missed your posts at that time. Very nice instruments.
Have you documented your buildings? I'm in particular interested in how do you "read" the "fake strings" strum and your usage of touch buttons.
For the touch sensors I use brass thumbtacks as "keys" and for the "strings" I use copper tubing. Both types acts as capacitance sensors.
For for controls (both latching and momentary) I use TP223 touch switches that are read as digital inputs.
I am glad you like the instruments. I will be posting the second part video shortly that will include: hang drum, wind instrument, jazz improvisation instrument that features scat singing, harp/lyre. I am finishing up Scottish bagpipes at this moment.