approaching diagnosis subject with my brother

Hi, 

My brother turns 50 this year and is undiagnosed aspergers. 

I have tried broaching the subject with him on a few occasions but he doesn't want to talk about it.

I feel he would benefit from a diagnosis but he just clams up and isn't interested.

He currently lives at home with my mother who is now 78 and it's got to the stage where she is struggling to cope with them living together. I feel getting a diagnosis may help as it would put my brother on the radar for potential help from the right people and possible financial help (if it's out there). He works part time on low wages so would struggle to support himself living independently due to finances.

Not sure exactly what I'm after but does anyone have any advice for me on approach and what assistance may be out there for my brother.

thanks

Grant