"Right off the bat, the use of a superscript in the first memo for "111th" raises a red flag."
I was a personnelman (typewriter commando) when I first enlisted in 1974, and used or at least saw every kind of typewriter in the military supply system back then.
A superscript was done by rotating the platen a half turn, then rotating it back to continue, but there was no way to make the chars smaller like MS Word does now automatically.
Except, perhaps, by using an IBM Selectric II, changing the type ball to a smaller font, then changing it back.
However, that wasn't done for the "th" up in the letterhead of the same memo.
As far as I'm concerned, the superscript is a dead giveaway. The fact that it only appears in that one place says to me that MS Word changed it automatically, and the forger didn't notice.
A woman on another thread writes that she used to type theses in the 1970's to earn college money, on a IBM Selectric, and that she would swap out the font ball to type smaller font superscripts, somehow rotate the ball only half a space.
But IMB Selectrics don't have proportional spacing. This type on these memos does. It might have been done on an IBM Executive, which does have proportional spacing, but you can't swap the fonts to get smaller superscripts.
We have gone through the balls and we do not have a "th".