Evan Prodromou
Unable to answer "Is Biblio-libre@Plein milieu still here? (Public Bookcase)" for https://osm.org/node/3355145122 via StreetComplete 31.3:

I don't see anything like this. Maybe a private business in the upstairs apartments...?

Attached photo(s):
https://westnordost.de/p/42113.jpg
https://westnordost.de/p/42114.jpg