Hi,
I just bought a 1913 Underwood No 5. After receiving it I noticed immediately that it was lacking an envelope guide - that little bit of metal that folds out from the center of the line indicator/ruler. Instead, I have a short, flat bit of metal that is attached firmly on the right side, while the left side sticks out and is held under tension by a very small pin. This pin is pushed vertically through two horizontal plates. The pin had nearly fallen out when I got the machine. None of this setup seems to have any purpose. I am wondering it it is the remains of what was once an envelope guide, or if some Underwoods were made without one. Here are some pictures:
https://photos.app.goo.gl/AxaSBSkDWTFW9vwt2
Additionally, there are no signs of the "Underwood Standard Typewriter No5" decals that usually adorn the very front of these machines, just under the spacebar. Again, where some No 5's made without these?
ONE more question: What is the story behind some No 5's having white-backed keys and some having white? Were they offered at the same time as different options?