Print this thread and the replies and give it to him.
Write in a seperate letter addressed directly to him what you have said here and all of the feelings you have. Often times people "hear" more when they have to read it and can't interrupt you with a justification, excuse or explaination.
Bottom line is that it sounds as though he is well under the clutches of addiction. He has all of the symptoms especially denial. A true intervention with family, friends and a professional can encourage someone to get help but in the end it is up to the individual to do the work...the hard part that no addict wants to do. One often wants to be clean but the work seems too overwhelming to get there.
You also may want to get some AA literature and give it to him. There are tons of pamplets on alcoholism and intervention that can be quite helpful. I admire your concern for him and your desire to seek suggestions on how to help. Good luck.
By the way, I can assure you, he isn't "proud" deep down there is a whole lot of shame going on covered by the "convincing bragg."