CSS custom skins to Gmod 13

So I wanted to import some custom CSS weapon skins from gamebanana since I was tired of the default skins, I dragged all the folders into the garrysmod folder like I would with the cstrike folder. It worked fine in game, the only thing that didn’t work, was aiming down the sights. Since most gamemodes that include CSS weapons in gmod usually include aiming down the sights, when I aimed down the sights, the weapon appeared to the very far left. I need some help with this, how can I make it so the ADS works with the models?