both blender and godot have their 3d collections, but not compatible yet. i see your piano, it would be challange playing 3d. the case can be in blender <5 i export in many glb files. Than do leveldesign the piano in godot, Keys, one sharp key, and white keys can be whole, left cut and right cut, animation not needed, because godot can rotate of press and release sound. Because the distances are the same, procedural use https://docs.godotengine.org/en/stable/tutorials/3d/using_gridmaps.html