We don't need plugin for adding skins, this plugin is already in server(or scripted into main mod plugin, idk how sky choosed to add it), but it is already in server, otherwise other skins wouldn't work too. Just need to add these new skins into server models folder and directing skin name from /models folder with line into script or into config file(when its added to plugin) and thats it. Be patient and they will come as i told sky got suggestions already to these guns tooSurely, you can make or add new skins into the game, especially for P228 and SG family guns.
Nice to see someone with actual code skills helping the community.