Other things to consider
Before you do balance a propeller, measure the distance from the inside of the hole to the tip of each blade. The distances should be equal.
If there’s a inconsistent between the two measurements (if there is, it shouldn’t be much), carefully sand back the longer blade until both sides measure the same. Retain the original shape of the tip.
Also, before you put the prop on the balancer, check that the prop is rotating evenly on the motor shaft/prop adapter. If there’s a noticeable wobble, it’s possible that the hole in the propeller is not perfectly perpendicular to the hub. This could be corrected with very careful reaming of the hole, but better trying another prop first.
Finally, make a conscious effort to look for vibration in your airplanes and recheck the balance of your propellers every now and again. Props do make contact with the ground every once in a while, and small pieces can go missing resulting in a new imbalance.
If a prop gets very badly damaged, never try a repair job. Always always replace the prop with a new (and newly balanced) one.