Try this: Lay a length of angle iron (available at any big box home supply store or local hardware store) on each side of the edge of the track. Secure them in place with some tape wrapped around the mast (fiberglass filament tape would work well for this). The angles should be thick enough to spread the force of the C clamps that you would then apply across the track on each angle. Clamp until the bend is gone. You may need to clamp further than the width of the opening you want at the end as there is likely going to be some "rebound" when the clamps are removed. It should not take long but it is the ideal time to enjoy your favorite beer while doing this so that you take your time and arrive at the gap you want patiently withoout overdoing it the first time. You may need to clamp and then unclamp more than once to work back to the original shape. Good luck. BTW, I KNOW that this works and that's all I'm sayin'.