for sail, I would suggest you can do valve lash and in regard to your injector, I would think a inspection
of each, in particular take them out carefully, we are looking for a trumpet that would indicate a few problems, but once you have established it is clean, wouldn't bother, if its got a trumpet, clean it off, the trumpet may grow again but unless you have blake smoke issue wouldn't worry.
Blue, there is no rubber gasket on HP side of Fuel pump
, nor is there copper, please check your drawings for correct identification.
small diesels is not my forte, but the pressures are more modest more like art than science