OK, stretching and shrinking is for a practiced person with the necessary training and skills. It's possible coolwhip could do it and it's possible he could chase an oil can all around the back of the cab or create the oil can from hell. I have practiced lots of stuff and still screwed up something. I would hate for someone to ruin a cab for an oil can, which may have a suitable fix. This is not a dent. This has not been stretched or shrunk by impact. (that I know of). It seems that the metal's properties may not need to be brought back. To me, this falls in the category of too risky if there is an acceptable alternative. (it seems to be a pretty old, maybe rare truck in good condition, not sure)
I may not be the only one who would not do it or trust someone to do it. A pro is someone who has done all kinds of that work on all kinds of metal problems. I'm glad you were able to do it with apparently NO mistakes. You are obviously very mechanically inclined with great knack. I would never advise someone to fix a oil can problem that way. Especially without knowing if it really is an oil can and how it is affecting daily life.. As I tried to convey, it needs to be known what it is and what caused it on a truck that is assumed to be designed not to oil can from the factory.
I am trying to be careful and give a DIY suggestion that will solve an oil can and not be an eyesore. So depending on coolwhip's skills, desires and equipment, he can drill some holes and screw some plywood on or all the way to shrinking/stretching with a torch or Disk.
BTW: You can make a shrinking disk from a stainless steel pot lid from Goodwill.
It really does depend on what this "oilcan" really is, where it is, it's size, what's causing it and so on.
Yar (or Ray spelled backwards), this a good discussion and commend you for offering to help/train the poster.
