The typewriter that Lexie used in the novel could well have been the Olivetti Lettera 22, which was designed by Marcello Nizolli in 1949, and won a prize in 1954, when the Illinois Institute of Technology awarded it the Compasso d'Oro prize for the best designed product of the last hundred years.
It was replaced by the Olivetti Lettera 32 in 1963, which was popular amongst journalists of the time.
One of the things that I had forgotten about mechanical typewriters was that they often lacked a key for the number one. This was because it was convention to use lower-case L as a substitute for the number one, which I now remember doing. It seems amazing nowadays, when keys on electronic hand-held computers are all multi-functional, and can create a huge range of symbols, letters, and even a range of little yellow faces, all possessing a different facial expression!