I recently bought the latch and top to the cover from Airstream. I would think that any competent body shop could somewhat smooth out the tank cover. Cost, depends on their skill and hours required. It might end up cheaper to buy a new tank cover. Personally the damage seems minor. I would just mark it down to battle damage and move on.
WBCCI 10656 Southeastern Camping Unit
Associate European Unit
2006 Safari LS 23 ft
Formerly 1964 Bambi II
"I got a fever and the only prescription is more cowbell"