Anyone have any expereince with interperting diesel fuel tests.

Everybody on the interenet wants money to explain how to read them. I have found some stuff that explains what all the tested items are but not much on what threasholds I should be looking for before I polish or replace the fuel.
At work I am managing our generator service contract so I am dealing with 2,000 - 4,000 gallon tanks fo diesel on 1.5 MW generators. Very cool big motors 2 detroit 92V16 and a Catepillar V16 pluss a hand full of smaller ones. Unfortunatley the tanks and generators have been neglected for the last 3 years

and as part of my new job it is my responsibility to get them back into shape.
Any advice or resource recomendations would be sweet.
Thanks
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2003 4x4 F350 Super Duty Crew Cab Short Bed
4" Down pipe and exhaust, Wicked Wheel, Modified Exhaust Turbo Housing, Big Head Waste Gate Actuator, PML Transmission Pan, Factory Tech Valve Body, Autometer Gage Pod, PHP FU2 Chip