Excellent point. I'm plenty old enough to remember that, and I would go so far as to say that "most, if not all" typewriters back then did not have a "1" key. I'd like to see a typewriter from pre-1975 that DOES have a "1" key.
(We should look AGAIN at the memo's (which post was that?) to see if the forger typed a "1" or a "l" ..........!