The Piezo bridge is a really interesting idea. Will be very interested in seeing what you do with that and how it sounds.

The one thing that I would consider, is NOT using 0000 steel wool, but rather using something like a Scotchbrite pad like these:

https://multimedia.3m.com/mws/media/...f-document.pdf

Steel wool can leave steel splinters, dust etc. It's especially bad if you use water based finishes because the splinters can rust. The sanding pads are cleaner and won't leave a residue that can react with the finish. They are also cleanable, so last considerably longer than sandpaper, and come in different grits.

I was not aware that working with bone (other than nuts) was similar to working with wood. Fortunately the prognosis when working with guitars is generally good, and the patient never bleeds or complains.