Just putting the materials in your materials folder won’t automatically set the weapon icon you know.
Why don’t you take a look yourself instead of disagreeing with my first post and giving the OP incorrect info? He’s said many times he wants to change the weapon icon in the weapon selection menu. :DrawWeaponSelection is the only way to do this with the default menu and every SWEP that has a custom icon either sets .WepSelectionIcon to a texture (which is drawn by the default :DrawWeaponSelection) or overrides :DrawWeaponSelection (look at the source! :hammered:).