'....his father's name is Robert Allen Parrish (Lance Corporal/3rd Marine Division)'
Have you considered contacting the Dept of the Navy? (They probably have a web Site). You may have to prove you are a relative and not someone trying an identity theft gimmick, but once you do prove it - surely they can get you a copy of hisapplication or enlistment papers - whatever they call it - and that should give you some of his vital stats. Good Luck.