1W6539, PUMP G, CATERPILLAR (Fuel Injection System)

In a very strange twist of fate, these PUMP G(s) remained untouched for about 02 years in one of the base stores of a utility company I am serving in. Anyhow, these were ultimately handed over to a very honest and a freakingly upright USTAD MECHANIC who utilized the same in a Caterpillar 3306DI Engine powering a Caterpillar D7H Track Type Tractor. To me the very name of this assembly deceived the hawks who are always on the look out to find and sell such precious items with names like Plunger & Barrel Assem or Fuel Injector Pumps in the local market unlawfully. 
This Pump G contains following components;
RING, 7W1927 (01 No.)
SPRING, 8N1415 (01 No.)
BONNET, 1W9171 (01 No.)
VALVE ASSEM. 1W6987 (01 No.)
SPRING, 7N1067 (01 No.) 
WASHER, 7N1415 (01 No.)