Item description:

This is my save after completion of the game and a little extra collecting
it'll unlock

'The Professional' All weapons fully modded and completely upgraded.
'Lethal' Purchased all skills in all categories
'No Stone Left Unturned' All documents, relics, and GPS caches found.

sorry i forgot to make a save before i got 75% of all collectibles and i dont think it unlocks those achievements.


When you load up turn around and walk back around to the bonfire theres a opened steel door on your left run and jump through it grabing the ledge of the hole in the wall opposite you in there is the final GPS caches, after that return to the bonfire and upgrade the last skill point and the last couple weapon upgrades,

You need to get the last GPS Caches before upgrading the weapons because it gives you 1000 salvage points otherwise there isn't enough to upgrade them all ( think there's 3 to upgrade)