I just received my Certificate for my Tiger from Coventry Transport Museum.
It lists for my car the Chassis, Engine, Body, Keys, Gear Box and Rear end numbers.
From the time I ordered via email it took about 1 month to receive the information.
You actually get a copy of the original handwritten factory records — mine covers 33 cars and a date range of 2 weeks.
To get the certificate just email email@example.com with your VIN for the car and your contact information including address. They will quote back to you the cost which is 60 British pounds. You can pay for the certificate by either giving them a credit card over the phone or they accept Paypal.