They do look (relying on memories from a few years and cars ago) like PS pipes that would fit the PS ram of a Citroen BX or XM. Maybe even Xantia - but I've never had one of those.
This was the only time Citroen used the finer pitch thread for their LHM system as the PS rams in the later cars were simply those that were used in Peugeots of the time but ran with LHM instead of power steering fluid.
Yes, they do look a lot like XM/Xantia/BX rack pipes, but part numbers don't match for any of those Citroen models. It may be that they're for the 405/306/406 series Peugeots of the same era, and interchangable, but I've not been able to search up the Peugeot part numbers.