Congrats, he's adorable! And I love the name.
I've had several rescues, and the best advice I can think to give is, start the routine that you want now, and stick to it. Routine is the thing most missing in a rescues life when they've had such a quick change as Ellington's had. And be patient with him when he gets clingy. That nearly always happens after they've had a little time to settle in and start to bond with you. They seem to get a little anxious, like they're worried you are going to leave them too. Good luck and don't hesitate to come here with questions.