Anyone know how we can tell if these are "typewriter" fonts? I cannot tell but they do not look like typewriter fonts.
This is what Courier font looks like, which comes from a typewriter. Those files were written on a word processor, because they don't look like this text.
You can tell by looking. In a proportionally spaced font, the width of each letter as printed is depends on what the letter is and is not uniform from one letter to another. In a proportionally spaced font like Palatino or Times New Roman, an upper case "W" is much wider than a lower case "i" or "l". In a monospaced typewriter font like courier, all letters are the exact same width. The development of monospaced fonts was necessitated by the technical limitation that typewriters advanced the platen (or the ball in the case of Selectrics) a uniform distance for each character. Monospaced fonts are measured by characters per inch, or cpi, 10, 11 and 12 being the most common in office documents. This measurement is completely useless with proportionally spaced fonts, except as an average. These memos clearly use a proportionally spaced font.