FOXNews has .pdfs of the "60 Minutes" memos here. Two memos have superscripts in them unlike anything I've ever saw done by a real typewriter in the 70s. But the most interesting thing to me is that none of them are on letterhead of any sort. I was Army (in the 80s) and I remember we had letterhead that was used for official memos. Curiouser and curiouser.