The 6E5 magic eye tube is usually dim or dead. Replacements exist (Russian 6E5S is a direct substitute), but they are getting expensive ($30-$50). A dim tube doesn't affect sound, only aesthetics.
Depending on the specific variation, the 111-07 utilized a complex system of levers, gears, and solenoids. When a user pressed a number key, there was a pronounced mechanical engagement. The carriage, if present on printing models, would slide with a solid, engineered precision. For many collectors, the auditory experience—the clack of the keys, the whir of the motor, and the decisive thunk of the printing mechanism—is the primary draw. It is the sound of work being done, a tactile feedback loop that modern digital devices struggle to replicate. admiral 111-07