The three parts for the Jaw are shown.
A good way of assembling it is to mount the head in a vice as in photo-39 and using the Neck-Pivot wire part #17, mount the neck in place. Hold the Bottom-Lip in place on the Top-Lip and place a Jaw-side in position then apply a small amount of glue to where it rests on the Bottom-Lip.
Be careful not to stick the lips together.