To keep everyone updated, I’ve since tried out several suggestions from different threads, but just to name two:
None of the suggestions helped,rake posts:rebake, rake posts:missing_uploads and rake uploads:recover_from_tombstone all did not work, unfortunately. I’ve also checked out the sidekiq dashboard, but that’s not restoring anything either.
To anyone having any idea how to restore the now missing images, I’d be grateful to hear them.