hi there, you could search on ebay under "xantia" ( i presume that's your car ? there are usually a few being broken, and they may be able to help you....
The xantia engine I've recently acquired (1.9XUDTE) had the clip-on type. I've just spent a lot of time getting rid of the tin plate and changing things over to fit the bolt-on type. So at the very least it depends which vintage it is.