Why the letter spacing matters
There appears among non-technical people some confusion as to the significance of the fact that the font pitch in the purported memos is the same as Microsoft Times New Roman. This is an attempt to explain that significance:
The fact that the letter spacing in the 'memos' matches Microsoft's Times New Roman is absolutely dispositive of the falsity of these documents. Not only could these documents not have been produced by 1970's-era technology; they could not have been produced in Microsoft Word prior to about 1992, when Microsoft licensed its version of Times New Roman from Monotype. TrueType (a joint Microsoft/Apple scalable font technology) was released in 1991. At that point, Adobe was in direct competition with its Type 1 technology, with a program called Adobe Type Manager which allowed PostScript fonts to render on-screen on Macs. Before that, although proportional fonts were available, they required separate bitmapped screen fonts in order to render in a pleasing fashion on-screen. Eventually, after some teething troubles on the 16-bit Windows platform, TrueType became the dominant player. The Monotype TrueType fonts that Microsoft licensed are acknowledged as being of very high quality. A word on terminology: Times New Roman is not a font. It is a typeface. A font is an example of a typeface in a specific style, at a specific size, for example Times New Roman 12 point Bold Italic. A particular letter shape within a font is known as a glyph. It must be understood that there are differences between typefaces from different foundries, even if the family name is the same. Monotype Times New Roman is different from Linotype's version.
The original Times New Roman typeface was commissioned by The Times in 1931 (note: it's not 'The London Times', as so many people in the US refer to it. UK dailies are nationwide, so it's just 'The Times'). Monotype got the job, and a typographer named Victor Lardent created the typeface. It was adopted by The Times in 1932. When Monotype created its TrueType versions for Microsoft, it chose certain design parameters (known as metrics) for things like width of strokes, size of serifs and so forth, all consistent with the original metal version, but very much sui generis for that particular instance of the typeface. Adobe and Linotype, in their licensed version, again chose certain metrics. To a casual observer, all the typeface versions look very similar, but they differ in certain respects. In particular, if the same line of text is typed in different versions, they will have slightly differing letter spacings, and the glyphs themselves will be very slightly different. This is absolutely crucial. That the purported memos can be recreated in Microsoft Word is not at issue (I've tried it myself). The important thing is that it can only be created in Microsoft Word. And you have to use Microsoft's TrueType version of Times New Roman MT. Adobe's version won't work. Neither will Linotype's. Oh, sure, they'll look pretty damn similar side-by-side. But overlay them, and it will be immediately apparent that they are not the same.
This fact applies, necessarily, to any hypothetical Times New Roman font available on 1970's technology. Monotype created its TrueType version of Times New Roman completely from scratch. Of course the design elements of the font were preserved - the letter shapes of the glyphs, the ratio of the x-height to the height and so forth - but the precise metrics were brand new. Even if a proportional-spacing typewriter from the 1970's, with a Times New Roman ball and superscripting capability could be found, the likelihood that the letter spacing would be the same is zero, nada, zilch.