VA/DAV, VFW, American Legion, AMVETs, Wounded Warriors....
If the "buddy" does not want to speak to a VA employee or public service veterans affairs specialist, he could also try the local VFW(veterans of foreign wars), DAV(disabled veterans), Wounded Warriors, American Legion post.
They may provide details about the gun/weapon issues but like I stated, I'm unaware of any firearm or weapon mandates re: VA benefits.
edit; I just reviewed a reported form re; veteran ownership of firearms, new SOP for veterans. The "letter" clearly states any "determination of incompetency" of a veteran means they can not own, possess, carry, use or store firearms & ammunition. The veteran(s) could face arrest or criminal prosecution if they violate the federal law(s).
If the "buddy" wants help or benefits, then he can't own-carry any guns. If he was screened/checked & has these medical conditions then he meets the criteria. If not then he can own or use firearms just like anyone else.
I think we are not getting the full story here.