like Jef sez, stay calm

if it's a factory style harness, it helps to lay out the works in the patterns that it lays in the truck, reduces the amount of confusion, like you only have to deal with the ones under the dash, or the ones under the hood, etc - length of the cables says a lot .... what you think are missing number on a diagram [probably meant for a number of different applications] will be there some place depending on what those numbers call for, some may be ones not included in your particular harness, pay attention to color .... it helps to have the factory diagram as a reference, it should have the color code on it, which is all you really need
for the accessories you're best off to have a fuse panel that they're fed from, and of course a factory 51 harness won't include any wires for optional accessories, especially electric wipers and fogs .... otherwise there'll be no difference in the original diagram from 6-12V
and check in the tech tips, there's one for the sig-stat wiring
Bill