you might be able to gently squeeze the part that got dinged back into shape. What you're probably experiencing is resistance due to the damaged leading edge. As long as it's not vibrating too bad you will probably be OK. Make sure there are no cracks in the covering. That will definitely cause resistance from the air catching in the crack. If there are put some tape over it and balance the blade by adding the same amount to the other blade (hopefully in the same place). You can get fairly close doing what Unitoo said. If I could get a stinking picture to post I could show you how I made a balancing beam from a longer 2mm screw and a piece of aluminum. I'll take some tomorrow and pm them to you if you want.