I think we've proven that it's Times New Roman. Now all we have to do is figure out when Times New Roman was invented... if it's after the dates on the memo, this thing will be disproven for once and all.
I don't think this angle goes anywhere. I'm an amateur fan of typography, having worked with it years ago.
IIRC, Times New Roman, named after the standard typeface used by the New York Times, was created for (by?) the newspaper in the early 1900s.
I'm sure somebody can dig up the full scoop.
Flash:
Nevermind: here's the full scoop. October 3, 1932 was first use.