These memos are useful for at least one thing:
The typing technology of the day made it difficult to center text (as with just about everything these "magical" memos do all too effortlessly).
Any complaints that the letterhead is too perfectly centered could be countered with the argument that the letterhead was pre-printed on the originals.
But the memo with the incomplete letterhead proves the letterheads were not pre-printed.
It's easy to speculate about the quality of Times Roman fonts available to typists in 1972. But it's impossible to center text that perfectly without a computer, even now.
Nope preprinted stationary would have had ANG seals on it.