I’m afraid I don’t have time to sort out my files and work out instructions, but here are my (messy) files for people who want to give it a try:
rdb.name/panda3d-webgl-build-depends.tar.gz
rdb.name/webgl-music-box.zip
The paths in freezify.py are hardcoded and will need to be adjusted to match your own build directories.
I did do some work recently on trying to make it easier to build for WebGL using deploy-ng; I’ve made some progress, but more work remains.