To take apart the actuator arm of a Mignon index typewriter, a soft-steel pin has to be removed from the hollow main actuator rod. This 2mm pin holds the 'plug' with the ball-on-a-needle that is the vertical type-alignment bearing. Only when that is removed, can the parts be taken apart further; the actuator arm in bits:
Most index typewriters were low-cost flimsy affairs, but the Mignon actually has a heavy cast-iron frame and is overall solidly-built.
It does have far fewer parts than a standard typewriter (and was about a third of the price), but it does have a similar build-quality. (Just wish that they hadn't used Zamac and pins!)