That's a possability but probably unlikely. Mulltiple copies tend to spread and get real rough edges. Also, pock marks in the drum cylinder tend to show up more and I don't see them. That's what makes multiple copies look old.
"Then when a new version was typed and overlain, it would fit almost perfectly."
In my opinion, and I'm as good an expert on this subject (not bragging) as anyone, this document is so doctored it is disgusting. I would say, at best, this is only a 3rd or 4th generation copy. I can tell by the small amount of size reduction.
Experts have not mentioned the Mag Card machines that were popular at that time. THEY DID HAVE PROPORTIONAL SPACING. And, they were popular in heavy production areas of the government. What you did is type it in with standard type and when it printed it right line justified with proportional spacing. But they didn't have these units out in the field so lets dismiss this theory. They were normal ball Selectricts out in the field. Nothing fancy.
The likelyhood that both printed images on this document are the same machine is ABSOLUTELY 100% ZERO. A copy was simply inserted into a more modern machine and information added. What a poor job they did.
I sold over a million typewriters and word processors for IBM, A. B. Dick and Lanier in the 70's and early 80's.
Are you wearing pajamas, sir?
"I sold over a million typewriters and word processors for IBM, A. B. Dick and Lanier in the 70's and early 80's."
Then you (and everyone) should be interested in this link I posted yesterday:
http://www.etypewriters.com/history.htm
The typewriter likely used by the TANG in 1972 was not the IBM Selectric, but the IBM Executive (Model A, B, or C) as discussed by Mineralman and others.
I note that several references are made to "size reduction" in a copier.
As I recall, the change in size is so you don't see the paper edge in the copy.
If there were a "reduction" you would see it even better.
Copiers expand slightly as I recall so the edge of the paper will be outside what is copied.
Nevertheless, for the close matches that have been done, it didn't change much.
I am posting this just to post a thought.
Copiers normally blow the page up a slight amout so the page edges don't show.
On copiers now, if you don't want to change the size, you just select 1% or so reduction. You may have to experiment some to get the exact percentage, but once you set it, you could make as many generations as you would like and the size would stay.