I'm not talking about the Selectric. I'm talking about the Executive. And a Freeper on this forum has relevant experience with this typewriter in this time period.
This is at NRO's The Corner:
Jonah:
Interesting theory, but...
When I was stationed at Patrick AFB (1971-74), I distinctly recall our office (Office of Public Information) had a correcting IBM proportional typewriter along with our standard-issue Selectrics. Nobody wanted to use the damn thing. It was a pain in the butt to use because to backspace you had to use a table that prescribed the number of "ens" for each letter for both upper and lower case. I believe (but I'm not sure) that the typeface was some form of Times-Roman rather than Courrier.
Before my recollections are questioned, I want to assure you that the AF Good Conduct Medal listed on my DD214 is entirely legitimate.
---
Given the existence of the Executive, and the Composer, I think that perhaps it is not quite a lead pipe cinch based on proportional font alone, though it remains exceedingly unlikely.
If somebody could attempt to reproduce this in an IBM Executive, that would shed some light on this. It has been almost perfectly duplicated using MS Word on a PC.
Despite the existence of the IBM Executive and Composer, the other circumstantial indicators this is a forgery are still glowing white hot, and all of them together make it rather compelling.