K.C.
I think you should speak with an attorney. I work for a Firm that handles probate and some social security issues related to that but no one was able to answer your specific question for me. I have a referall of Ken Dobbs who is an attorney dealing with social security issues. You can reach him at ###-###-####.
Good luck. It's very honorable of you to help this boy and I hope everything turns out for the best.