what should I replace first diesel pump or fuel rail to 3ltr 2006 diesel ve?

Vauxhall dealer found code after tech 2 testto be code for fuel pressure range/performnce.carried out TIS checks on fuel and intake system,test showed pressure regulator faulty but when road testing actual fuel pressure is only getting up to 18.25mpa,desired reading 68.13mpa under load.They said only component that controls this isthe fuel pump but fuel rail may also be damaged.Minor traces of swarf found in fuel filter housing.Injectors ok as no misfire,they suggest replacing fuel pump,rail,pipes sensors and all necessary parts. Is a fuel pump repair worth considering