The two human body parts that are also found on a typewriter are the eye, or "i", and the finger, or "paper finger" on a typewriter. The "i" key sounds the same as "eye" when spoken, while the paper finger is a clamp used to keep the paper in place on a typewriter.
"Paper finger" is defined as "one of two movable clamps on some typewriters that are used in place of or in addition to the bail to hold paper firmly against the platen". It's sometimes referred to as simply the "finger". "Finger" may also be correct because when one uses a typewriter, they place their fingers on the keys of the typewriter. Technically, you could also say that "hand" and "finger" are correct, since these two body parts do press or lean on a typewriter when someone uses one. But since this question is a riddle, it's implied that the answer is figurative.
Artist Jeremy Mayer has made a career out of reassembling typewriter parts into sculptures resembling human figures and animals. His work can be viewed at JeremyMayer.com.
A documentary film about typewriters was released in 2012 and is still showing in select theaters across the U.S. This documentary, The Typewriter (In the 21st Century), explores the recent history of the typewriter, its downfall due to computers and word processors, and the small segment of the population that still uses typewriters regularly. Information on the film, as well as screening times/locations can be found here.