Looking for opening dimensions of an original MK2 Webasto folding sunroof

I am seeking to install an original type folding sunroof in a 1960 MK2, similar to the Webasto folding sunroofs as supplied by Jaguar.

I may have found one, so I am requesting if anyone in our MK2 community that has a MK2 with an original Webasto folding sunroof to measure the opening (length and width) when the roof is totally opened. Also if one could measure from the center of the windshield top to the front center of the opening. This will give us the placement then for the opening.