Installation: Copy models and cleo folder to VC root dir. You must install cleo from http://cleo.sannybuilder.com/ If you want to use iv-style icons, rename iv_hud.cs to iv_hud2.cs in your CLEO folder. Next, using any IMG Editor for Vice City (I recommend G-IMG), import the gta3.img files from the wpn_models_and_textures folder. If you are using original weapon model numbers, extract it from gta3.img, change icons (from icons.7z) to txd file via TXD Workshop and import it into gta3.img.
Thanks: yojo2 for HQ radar icons and Reborn for G-TXD tool. RollY for New Headquarters Weapons, Icons. Alexander for San Andreas, GTA IV HUD.