It all depends on your goals, your skills and your ambition. It is your car and you have your own goals and expectations. It is not up to any of us to define your goals, but rather to describe your options. There is a difference between restoration and repair. Restoration means returning the metal as nearly as possible to original condition. Ambition means you can learn a different or new craft if you invest your time into learning new skills.
My goals of keeping my "historic" 82 Dodge pickup capable of fetching drywall sheets or mulch from the home center differ from my goals and expectations compared with my Firebird. I wouldn't bother with restoring my 82 D150 but I would keep this Historic truck going down the road. If the truck had a hole in the floor, I wouldn't restore it, but I would stop my feet from falling through the floor. (Well I might butt weld it for the experience gained, but not because the project was worth the time) It's a historic truck, but not really a collectable worth lots of time.
"Historic" does not mean a car or truck is valuable or worth heroic effort. That depends on the condition, the cost and the future or potential value. Shiny paint on my truck and repaired makes it worth around $1000 compared with $$750 as she presents without an undamaged panel anywhere.
If you never butt welded a panel, you won't likely walk up to your Firebird after buying the best welder on earth and repair rotted sheet metal parts on the first try. Lap or flange welds will be easier and take less experience, but without some experience, that's a disaster waiting too. Welding is about connecting with the liquid flow of metal, and you need to gain that through experience because while we describe MIG as hot melt gluing with metal, that's not really the truth. I guess I spent a few tanks of gas through the MIG welder before working on my car. You might be a better student and only need to spend one tank of gas before tackling your project, but your car is not the best place to learn the craft. Get a welder and practice first.
