Hi Roland, Not seen any original coachlines at dealers but a few occasionally on eBay. The pic above of an eBay listing is for reproduction coachlines.
The originals came in 8 sections and cost £250/300 many variations but mainly pre HE ( no side repeater indicators), pre 1986 were thicker stripes as per eBay listing above, 1986/87 were thinner and the Sportspack different again with colour combinations.
My Jaguar Parts Catalouge is a later version – suits my 1987 car – so I can’t see your correct colour for a 1985 model.

Have a look in your Parts Catalouge, right at front afterbody/trim combinations. If you don’t have a Jag Parts Catalouge buy one as best £30 you will spend, honest!!
I’ll post a pic of the colour chart for later cars but doesn’t show your specific grey..
Robin