Lots of good advice here.My only addition would be to go see him and do it in person.You are only going to do this once. He will be impressed and should solidify your position if it is not already.
Jim, just came over from OB. Good to see that you are here. I miss your posts. Caught any fish? Need to see pictures. And I hope that Mack allows himself to go out gracefully whether on his terms or not.