Here's what I would consider:
Get an estimate from a body shop, claim on his insurance. Take the cash for DIY. Be sure to also include a diminished value if this is a first collision.
Then, you have a number of options. In no particular order:
- Do nothing and leave it (personally I would have to do something)
- Pound it out to near shape and paint any damaged spots. You'll never get it quite perfect via this method but you can get it close to normal-looking with maybe 4-5 hours of effort and a few basic tools. (I would only do this if you consider it a beater jeep, which I'm guessing you do not.)
- Do a full body-shop style restoration, and cut out the entire damaged area, and replace it. If you know what you are doing, you can make that area pristine. (This is a lot of work.)
- Pound it out to near shape, spray over any paint damaged spots, and add corner guards. I've always liked the aluminum ones. You can have them painted to match the body. You can even paint the fastener heads too, much like the windshield bolts. (I personally would do this.
- Get around to doing that 5-12" stretch you've always wanted to do. At 5" of stretch, you'd still be able to use a stock gas tank or a 24 gallon aftermarket tank. Further than that and you will need a stretch tank. (Genright makes a 26 gallon stretch tank for the LJ.) Since you'll be cutting into the sheet metal anyways, this is the perfect time to start your stretch project.
- Go ham and get a whole new tub. Some aftermarket vendors are even making aluminum tubs.