Adding .dds weapon/mag/shield skins with texture manager.
Since it is a weapon/mag/shield skin texture.
Open texture manager.
Open file psobb folder/data/ItemTextureEp4.afs
Next a box will pop up with a bunch of numbers, select the weapon's number form this list.
ItemTextureEp4:
Then it will open all the sub textures for that weapon.
Select the same textures that match the name of the .dds skin on the left hand side. then import .dds  select the skin you wish to import.
If importing more then 1 texture at a time a new box will pop up for you to confirm which textures to overwrite make sure then numbers on the left match the numbers on the right.
Now another box will pop up leave everything unchecked this box and hit ok.
Then file save as .afs save restart pso and it should work.
In this example I will skin texture 082 - Hildebear's Cane for Odie rod.