You're awesome!
In the 1970's, I used IBM executive type electric typewriter with variable type. The elements I am aware of were prestige elite (serifs), courier (sans serif), and italics. I had to roll the platen manually to make superscript numbers for footnotes. It was very difficult to make two superscripts next to each other. I was only aware of 12 and 10 point fonts. 14 or 16 point fonts would have been necessary to make small superscripts as I've seen in pics of the bogus documents. I am not aware of the availability of those size fonts.
Keep up the great sleuthing!
The IBM Executive has been conclusively ruled out in other threads. 1. The font here wasn't available on typewriters back then, incl. the Executive. 2. The fonts here are kerned - not possible then. 3. There is proportional line spacing here, also not possible then. 4. The overlays ...
The story is now wheeling from whether they are forgeries to whodunit.