On this parts fiche the Guide,valve Osz is the most specified component.
A sample from the products for the Cylinder Head (front) include: Dowel,pin,12x20, Bolt,flg.,6x39.5, Screw,cross 5x28, O-ring,26.2x1.9.
The Screw,pan,5x25 is the lowest priced item on this Cylinder Head (front) schematic.