rust prevention

Hey guys I've got an obscure question. I have a rust patch on my left front fender of my 76 dart. It has created a small hole and I'm looking to keep the rust from spreading. I'm really not looking to cut/grind it out and fill it, as I'm not really planning to restore this car right now. For right now I'm hoping to preserve the car exactly as it sits and keep it all original. Any thoughts on what I could do? The car is garaged and only driven when the weather is permitting (it's only been caught in the rain a few times). I have this one patch on my fender and also my left rear quarter panel is kinda rotten as well. I was thinking just POR15 it, clear coat it, and undercoat the backside.of the spots...anyone see an issue with that? Thanks in advance.