It has been said that if you make a pair of hard wooden blocks that you can clamp them around the tube in a vise and twist the frame a bit you can remove small wrinkles. I have tried it and it works. On butted tubes, they kink at the end of the internal transition (about 120mm down the tube) or very close to the head tube in the thicker area, sometimes both. It sounds like your damage is very slight. I would prefer to see a clean side view photo of the bike to see exactly how much it have been altered before passing my opinion along as to it's structural integrity.