Anyway not sure how much use this may be but the openings for both rad fan switches and diesel waxstat (cold start cable) are the same.
Perhaps you have a radiator with a hole for a fan switch and no blank, in which case a later 1.9 Xantia or any XUD 406 will provide a blank from the thermostat housing (as these do not have the wax stat usually) or maybe vice versa perhaps you want to blank the thermostat housing opening up.
Random thought: Don't fit a fan switch to the thermostat housing instead of a waxstat, I did try this on my 205 simply out of interest / curiosity and the fan ran far too often.