Wow this looks like my old car - I sold it around 2 years ago when I got my current 1992 V6. Nice to see it ended up in the hands of an enthusiast.
If it is my old one it's a 1994 (produced 1993) Mk1.5. It should have a Mk1 bumper and nose cone however when I got it had the S2 nose cone. I believe it has had a new bumper and panel work since I sold it but it does still look like a S1 bumper. The colour is Sable Metallic (code ECZ I believe) - only used for one year and a rather rare colour.
It was originally a Telecom NZ company car and went private after that. I purchased it April 2012 and sold it around August 2015. When I purchased it the exterior was in rather poor condition (and unfortunately stayed that way during my ownership) however it was well serviced by a Citroen specialist here in Wellington. I sold it to a man in Levin who had owned several XMs was prepared to spend some money on panel work. He also put a set of 24v wheel on (it originally had steel wheels and the owner previous to me put S1 alloys on it).
https://imgur.com/a/pxugP - here is an album of photos mostly, from the original TradeMe sale. The first one is from when I sold it (with my V6 in back)
Unfortunately I can't help with the fog light glass - my passenger one is also damaged and repaired with a piece of flat glass but it has always passed a WOF.
I always slightly regretted selling that XM. The suspension and gearbox were exceptionally smooth and it was a nice car to drive (with a mint interior too, even the glovebox latch, strut and keypad cover all worked). However having two XMs was impractical and I do like driving my V6.
Jordan.