So you're set.
Campagnolo made a special stepped ferrule that was a very snug into that fitting, and kept the housing correctly aligned. I doubt you'll be able to find the exact item, but any snug fitting stepped ferrule will do.
Note, a sloppy ferrule will tend to go offline because of the tug of the housing, but if it's an issue, you can creatively find a way to make the fit more snug so it works well.
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