Bert - You're right, the drops are big and quick and the increases are slow and low.
What helps a lot is simply time going by. The more chronological distance between you and the BK, the better your credit.
You didn't give us your whole credit picture, so it's hard to tell what else is going on. What was the result of the disputes? It may take a while for inaccurate info to be removed or updated. Getting the new credit card may result in a temporary score dip, but once you start to use it responsibily your score should start rising. Charges small amounts, pay them off, and keep your utilization low (and your powder dry LOL). Good luck!