[Constitutionalist Conservative]

The use of proportionally spaced fonts did not come into common use for office memos until the introduction high-end word processing systems from Xerox and Wang, and later of laser printers, word processing software, and personal computers. They were not widespread until the mid to late 90's.

I dunno, maybe we were special, but our family had an IBM Selectric typewriter in the mid 1970s that did proportional fonts.

Just a minor nitpick which doesn't take away from the rest of the analysis.

[Constitutionalist Conservative]

I dunno, maybe we were special, but our family had an IBM Selectric typewriter in the mid 1970s that did proportional fonts.

Sorry for the brain burp. It was an Executive, not a Selectric. Long gone, along with a lot of my memory. :-)