The reason that a 760 is at the 63% percentile is because only people who are really good at math take Math II. It is similar to the fact that 43% of the kids who take AP Calc BC get a 5, while only 19% of the kids who take only AP Calc AB get a 5, even though it’s only about half the material of BC. For Math II, even a perfect score is only the 79th percentile.
You are in the top 37th percentile of the kids with the strongest math skills.
So no, I wouldn’t recommend that you take it again, though others may have a different take.