Rare Jaguar MK1

Hello

I have a Jaguar MK1 from 1957 which has the peculiarity that the rear windscreen is bigger, like a MK2. This car left the factory like this, it is seen that it has not made any modifications. The rear glass does not have a manufacturer's mark so you can see that it is a prototype and that it was made specifically for this car.

Also we known that 'The Jaguar Heritage Trust' company told us that the bodies were built by 'Pressed Steel' and that in the development phase they experimented with different configurations to ensure the roof had the required strength, but that they don't have detailed records...

Does anyone know how many vehicles were manufactured with these characteristics?

Also add that the vehicle is for sale to restore.

Thanks!