Dear MnN,
It’s late and I’m very tired, but I want to post some things on your thread because, to be honest, your situation is so very frightening to me.  Please forgive me if this seems blunt or seems disjointed.
Apparently your brother does not recognize that he has a very serious addiction.  And you and your wife have not been part of the wreckage caused by his addiction. You are just learning about it yourselves.  So I am wondering:  Are yall doing this just so he has food and a roof over his head,  or are you doing this to give him the opportunity to stop gambling and get his life back?
Either way, I think you should have a Plan B that you all can agree on, and know (and define to your brother) what would cause you to put it into action. For example, is there some sort of group housing he might qualify for?  
Also, I think if you allow him to control his own money that  1) you will seldom if ever get your rent from him, and  2) he will find a way to gamble it away and will then ask for money.  You could ask him to have his SS check directly deposited into your account and only give him small amounts of money at a time (or some similar arrangement).   You would not give an ********* a bottle right?
From your last post it sounds like your wife is very caring and very fair minded – unfortunately she also sounds very naïve to this horrible addiction – and it will eat her alive.  Everyone here and anyone who has ever dealt with or been a compulsive gambler will tell you the only chance you have of coping with this addiction is to know and understand it. And as Velvet advised, the two of you must be united.
Once the “honeymoon” is over, be prepared for the lies, anger and resentment when you enforce the rules and put up barriers, and have some idea ahead of time how you will deal with them.
I think it would be a good idea to determine the time and place of GA meetings (I heard it is a good idea to confirm the meetings with a phone call if possible) and make arrangements for him to get there. If they are “open” GA meetings you can go with him.  And consider going to the Gamanon meetings yourselves.
And lastly, find  a good therapist specializing in compulsive gambling if possible, speak to them and have that information readily available.
That’s all I can think of right now. Hopefully you will find some of our experiences and suggestions useful in your situation. 
I know your brother will be there soon and I do hope this all goes well for your family.
Please let us know and keep posting. 
 "… should I give up or should I just keep trying to run after you when there's nothing there?"  Adele– 6/9/2013 3:48:01 PM: post edited by adele.