Hey Andrew, just a quick tip you might like: when using fabric instead of felt on a piano, I find it sounds way better if you cut it into pieces in places where there are no hammers on the mechanism. This way, when the hammers strike the fabric, you won’t get a resonance / slight noise from the strings nearby. Also, pasting the fabric under the lid, as close to the strings as possible will help with that even further and will make the note sound cleaner
Or at least that’s what happened with my setup.