Man, that is a BIG ASS Heinrich tank.
I'b be tempted to restore it to its' original shape / condition as long as you can find someone to do it correctly.
If you bought it "right" it will only increase the value. ...but if you use it as is...and scratch it up, that will just add to the "patina".
I have a smaller Heinrich tank with the top tool box.
I found reproduction tool box covers but opted for a used, slightly beat up original.
The dents / dings give the cover "patina" and character.