This guide will remain a memory of the items I can no longer get and lost a long time ago when I decided to go to the bathroom and leave the PC in the hands of a guest. Of course he was interested to play the only game I told him to not and the first thing he did was to play with the inventory, crafting and deleting random items...
Obviously there's no chance that Valve would give me these items back, so do a pray.
The moral of this story: Do not leave the guests unattended if they are playing on your computer.