I sold my XJS about 5 years ago but still have manufacturers service manual. It is 4 big green books. I paid 200 for them. If anybody interested email car5car at hotmail dot com I can take pictures of books. I am pretty sure it was from 76 to 89 manual. I'll check it out tomorrow.
I would like to get some money back so let me know whatever you feel like paying. If highest offer will be $5, I'll sell it for 5. I am not planning to buy another XJS.
I had 86 XJS, I drove it for about one year and I had 76 but never made it driveable.

 

Manual is from 76 to 88. Books were printed by Jaguar in 88.
It is possible that there is no difference between 88 and let us say 92 but it is up to you to find out.

 

89.5 and up has a different ignition system.