I'm a beginner and trying to find the best way to repair the rust around my front and back window. I've never welded before but I do have a Lincoln 140 MIG welder. So far I've removed the front windshield and can see the damage. I will be removing the back window soon but can tell in the cornerns that I'll need to weld in some new metal. I've attached some pictures to show what I have so far, and I'm looking for some good suggestions on how to proceed with this kind of repair. The rest of the roof is in pretty good shape, but in the rear of the roof there is a lot of filler that was used by someone who repaired it for the owner before me. Looks like the vinly top dug into the metal or something.
Would replacing the entire roof be a good idea? Or would patching in some metal for the rusted areas be better? Or is there a better alternative?