I can't imagine anyone doing that..........but then I don't have to imagine it!

 

Webasto were an after market supplier of sun roofs in the 50's, 60's & 70's and I think they are still in business today doing the same kind of stuff.

The big Jag saloon cars from that era, Mk4 /5 and Mk 7-8-9 quite often had webasto steel sliding sunroofs fitted, but I don't know if Jaguar had them fitted at the factory or owners did it after purchase.

Also you could get a fabric folding back Webasto sun roof on Mk2's back in the day.

Just some trivia....I think I'll go watch The Dead Zone now....

 

The Webasto fabric sunroofs were the standard ones fitted to the series 1 and 2. Not sure if they were factory fitted or dealer fit.
You can still buy and fit them but they cost a lot and the fitting is complicated to say the least or expensive if you pay a company to do it.