If you haven't already, you can access it by clicking on the address above or cut-and-paste (on arriving, the first thing you'll notice is that his name is misspelled).
Also, the information re National Archives applies to records of individuals who served prior to World War I - mainly Civil War veterans. Service records and pension files, until recently, were $10 each. They're now $14.50 to $37.50. This is all irrelevant, however, inasmuch as Ruppersberger was a WWII casualty.
You've discovered by now the web attracts an abundance of erstwhile "experts" and plain busy-bodies who readily offer "free" information - heresay and misinterpretation (at best) -which is usually worth every penny you pay (i. e., nothing).
Sadly, these individuals, in their zeal to gain notice, "help" others or whatever their expressed aims, remain blissfully ignorant of the fact that they usually succeed only in adding confusion to already confusing situations; exacerbating the very problems they profess to be trying to solve (not to mention creating new problems for others in addition to those they're "helping"). Sheri and Turner's (as usual) "advice" is pretty much like Ray Charles driving and Stevie Wonder giving directions - you're not going to get very far.
If you're seriously seeking info and answers, order his deceased file as instructed and, when it arrives, take whatever useful info it contains and use it to go on from there. Period.