[mirwa]

I have four broken headstocks similiar to yours in my workshop at the momment, it is a very common thing to happen.

I would personally, as its painted and no wood showing ,do a graft in the repair, that is reglue the headstock first, then take a scoop of wood out across the break line and then lay a piece of clean smooth wood into its place, plenty of strength and less likely to crack again on the same break line

Steve