Use Spark IV to add this icons to weapons.img file!
I hope if everyone know how to do that!
Don't forget to make a backup!
In v2.0 icons are made for all weapon retextures on GTAGarage.com site and for all default weapons from GTA IV!
in weapons.img file are rpg.wtd, ak47.wtd etc. if you open eg. ak47.wtd you'll see the textures. In these all vaerious textures you'll see the icon.png. AND YOU REPLACE icon.png file and you have to save the changes and save the weapons.img, and exit the Spark IV. The same you are making with all weapons! You understand?