The warning that straightening it a few times is causing fatigue is not correct. Fatigue comes from thousands of bending stressings. A few cases in going beyond yield (of course you know what that means) work hardens it, raising the yield point in that area so the next bend might be a little further up the ram. If you can straighten it to near original shape, it should work fine. Check the diameter at various locations (like nine, 12, three o-clock) around the shaft and it is nearly round, fine. But if it is far out of round, the seals may leak too much.