Michael,
I am sending you a list of about 10 excellent vendors for Jaguar parts out of forum. Most of these guys are on the mechanical side. I have more for the soft ware side (interiors, etc)
A word of caution regarding your new Jag. You MUST take a moment from the excitement and take a LONG hard look at what it is that you want to do with this car. It is indeed true that a show room condition XK140 will bring upwards to $100,000, but if you are going for that kind of value -- be prepared to spend that kind of money to get there. If and when the car achieves that kind of condition, you must then find some one who thinks the value is equal to what you think it is. Take a moment some evening and just cruise through the Ebay ads and see how many people are selling cars with descriptions like " $25,000 invested -- must sell for $10,000!!" or some thing like that. You MUST take the time to decide exactly how much you want to spend and over what period of time you are willing to spend it. Most Jaguar restorations are a labor of love -- very, very few are actually investments. A Jaguar is a very poor investment. You would be smarter to figure out how much it will cost to restore the car and stick the money into a money market. You will get a better return.
Two years ago when I went to a seminar at the national Jag meeting, they had a restoration group give a lecture. They started off by citing a recent case where a guy brought in an XK150 for a restoration quote. The basic quote, with caveats for increases as they got into the car was for $150,000. The paint alone was over $20,000. This was to make the car a near Concourse quality vehicle -- Pebble Beach style.
I don't mean to throw cold water on your enthusiasm, but I have seen way too many people get into these cars only to run out of time, money, enthusiasm and money. There MUST be a reason the previous owner re-built the engine only to give up on the project. A friend of mine just re-built his engine back to factory specs for his Mark IX. Total cost $5,000.
In my own case, I have been sitting on my S-Type until I have the funds to restore it back to original. It has been two years sitting in the garage now and counting. I estimate that it will cost me in the range of $45,000USD and the car right now is a running daily driver. In the meantime, I have re-done my 420 as a kick-around car and daily driver for my self and my kids just to have fun it. The total cost to bring it up to speed with paint and interior: $6,000. But I won't even drive it to a Jag meet because it is just a fun car and not worthy of Jag owner's scrutiny.
Take a deep breath and start making some plans. Restoring the car will be like starting a new business -- it takes planning time and investment. If you are planning to farm out work -- triple the cost of you doing it yourself. As one of the other posts said -- this is NOT for the feint of heart!!
Cheers
Clark