What do you want to bet that any typewriter fonts exactly match the spacing of TrueType?
The odds that anyone would have produced produced a font, in any form, before 1972 that would just so happen to match the metrics of a font produced over a decade later are basically nil. But fonts certainly could (and did) exist wherein one character could overhang or intersect the next.
Clearly the documents are fake. Any reasonable person who examines the evidence would reach the same conclusion. But that doesn't mean the claim about overhangs being impossible is right. Indeed, if there was an italic version of the Executive produced, I would be very surprised if none of its characters featured overhangs.