Edited on 2014-11-19 0:20:04
Tony
In the US, Federal law prohibits the release of personal information (i.e.- names, addresses, phone numbers, etc.) of car owners without a court order. So, you're going to have to put on your Sherlock Holmes caps and do some old fashioned sleuth work. :-)
The Heritage Certificate is the best starting point. Jaguar is a bit unusual among auto marques for still releasing records with the name and city of residence of the person who first bought the car. Once you have that, there are various online resources available to locate the person (if they are still alive). At the same time, you can search backwards by using the title docs that should have come with you car for the name and address of the previous owner. Then, try and contact them and go from there. I've been in your situation wherein the previous owner, for whatever reason, is uncooperative. At times, I have been able to talk them into giving me another valuable clue (if for no other reason than to get me off of their backs). But sometimes, the trail goes cold.
The bottom line is that there is no easy way to recreate the ownership history of a car. It takes patience, and often, a good deal of time.
Good luck!