I can only but assume you are reffering to the injection pump?
There are places which speacilise in reconditioning of IP, turbos etc... if you plug "diesel recondition *your area here*" or "Lucas diesel recondition" see what you come up with. I had my Lucas CAV done about 4000miles ago, gave the engine a new lease of life, completely overhauled... that was at Lucas in Glasgow.