You will need to be patient! The pick marks don't look too severe. Try to dolly them flat. If you stretched too far try heat with a torch in a dime sized area to a red hot and quench. It May work. I haven't used a shrinking disk but it looks like it would work also. That line is a hard area to match. Try building one side with filler, sand and finish and tape a straight line on and match with filler. Sand and finish. Go slow and remove a little at a time. As all said above not a easy repair. Take your time and you should succeed. Good luck and have fun
Dan
