yep, nice question (the manuals)
i carried the stuff around. in inventory and/or in the truck but it kinda was to no good. I was putting my hopes in the mechanic in Ciad de Oro or something like that but that one was a fail

, hoped for the same principle as in E5.
No good. Personaly they could had at least set that papers to be readable and afterwards increase skill in those thing lets say by 1 or improve some of the handlings of the character like faster shots per second, faster reloading, faster cleaning or ataching and detaching of the addons or at least to improve the care of the char for the particular item so its easier to keep it clean for longer or decreased propability of jamming the gun when its dirty like s..., or even to improve damage of the weapon and so if the character who read the manual is carrying it.
Maybe once someone will figure out how to implement something from the above.