Originally Posted by xintersecty

My two cents.
1) Clean what you have, don't remove anything. You need to figure out what you have. A drill with a cone shaped wire brush will work nicely.
2) Once clean you can determine what metal is good to keep and what should be removed. Remember rust is a metal cancer.
3) Use cardboard to get the right shape for the bottom.

That should get you started. If you make your own pan from fiberglass or sheet metal.

The right way to properly repair this, is go to the junk yard with a battery operated grinder/cut tool and remove an existing pan from a cross fire with front damage. Ideally you would weld it but the SEM mentioned above is good idea. You can take your scavenged pan and press it in to fit.