Your score went up because you paid the balance owed, so it is no longer being factored into your overall util. Once the charge-off is removed, yes, you will likely see a significant score increase (25+ points) as a charge-off is one of the worst types of derogatories (some see a decrease if the chargeoff is one of their oldest accounts, as it reduces AAoA; some see no score change because the points gained from removal are neutralized by penalty of a reduced AAoA; most see an increase). But it's very rare to have an OC remove a charge off unless you can prove substrantial reporting inaccuracies -- and even then, they are more likely to correct errors than remove the tradeline. But you can try a Goodwill - you never know.
Even if you are unable to get it removed, your score will recover as time goes on. The account is now truly closed and therefore, will no longer be updated by the OC -- allowing it to age and reduce damage to your score - though it will hurt till the day it is actually removed.
