https://myoldtypewriter.com/2018/08/05/adler-j3-please-release-me/

Adler's have a quirky locking mechanism for helping to lock the machines into their cases and after decades of storage, the rubber can compress thereby locking the typewriter into the case permanently. Removing the e-clips internally will unlock them at which point the rubber compression locks can be replaced.

The article mentions other incidences of this. Another example at https://new.reddit.com/r/typewriters/comments/1fckg8f/removing_triumph_gabriele_1_from_case_base_plate/

Crawford 25108 E-Ring and C-Clip Tool 8-1/2"