Patch panel

[truckin 79]

I was replacing the drivers side fender because of rust and knew I had some in bottom of door as well. The more I kept picking away the worse it got, now it looks like a mouse hole. As you can see my previous temporary patch was ALOT of bondo. It looks like what happened was that knockout they put in the panel fell out and all the water and road debris just sat inside for years. I knew I had some rust so I got a small patch panel from junkyard, well it is way to small. The rust extends from what you see to almost halfway in-between the door. I had noticed a 1984 suburban in the junkyard the last time I was there. Is this lower part from the 84 burb the same as the 79 c10? All this while I am trying to put AC in the truck on the cheap which is costing more and more money LOL. If anymore holes pop up I might not need air conditioning