You might want to see if you can find a magnet or some kinda magnetic tool that you can get into the headlamp assy. with & fish around in there for awhile. Several other members have had luck in doing so. Most of the time the clips come zipping off & drop right into the assy. itself.
Beyond that, 180's idea of manufacturing your own might be the only way to go.
Good luck & let us know what happens!!