I guess for the environment Dustbowl is a good try for a NV-ish world, plus use the Bullpup Bozar, Caravan Shotgun, Varmint Rifle, and NCR Ranger Armor, and NCR Trooper armor mods in the nexus and I think that's the closest to NV as it can get. Fallout 3 or New Vegas-ish within Fallout 4? The game is vastly different from those games though, so I don't think its possible to do that even with mods in mind.