The volume mute/up/down keys have no keysyms assigned to them. They have keycodes 0xa0, 0xae and 0xb0. Binding them with in the keybinding capplet works fine, though.
Here is a patch that adds a geometry description and suitable symbols definition to support this laptop
Created attachment 134872 [details] patch
The patch is still missing two things: a) an entry in base.xml b) the overlayed number keypad is not represented in the geometry yet
Created attachment 134878 [details] new patch The second patch add the model the .xml file. I decided to not worry about the overlays for now, since gnome-keyboard-properties is not displaying overlays anyway.
Fixed in rawhide, and filed upstream