Having cleared up the lack of a #1 on pre modern keyboards, and taking a closer look at the documents posted here, I do see Vladm's point, though.
The #1 and the lower case l are not the same on these documents and they would be if typed on a machine without a #1 key.
There is a definite bar on the bottom of the lower case l and there is none on the the 1, which is opposite of what I just typed as an example. My #1 has the bar and my lower case l does not.
That is not to say that there was never a typewriter in 1916 that did have a #1 key. There may have been one with that key as so many different companies made typewriters and each tried to make their model different. Not so today were we strive for conformity.
I wonder why, in their infinite wisdom, the creators of the early typewriters left off a #1 key and how they determined that a lower case "l" would suffice in its place. I know that the random spread of the letters was done by someone who just tried to mix up the alphabet as best as possible, but I think he failed to realize that the most used keys are on the left hand and that right handed people out number left handed people. There are entire words that can be typed on the left hand only. With the right hand only, not so many.
But I digress, yet again. So Vladm makes a valid point about the lack of #1 key on the typewriters he has posted and the documents that he is comparing them to. If that document had been typed on a machine in 1916 and that machine was like the ones shown in his post, then the #1 and the lower case "l" should be identical. They are not.