This is the Corona 3 from which I obtained the Rest key. It sort of works now. It types a little blurry, but that is how they caught robots in the early 20th century. It is similar to the CAPTCHAs we see on websites. Only humans can read it.
This one is an interesting one because it has a proper carriage return lever, automatic ribbon reverse, and no nuts to retain the spools. The evolution of typewriter designs can be quite interesting to follow.