"The sunroof switches in my twinny (1996) are on the same bit of plastic with the interior and map reading light."
In that case, its definitely not original. The switch itself looks like the Alfa window switches, though like I said, its just stuck there on the headlining. He found a leaflet in the car last night and the sunroof was made by a company called Vermeulen Hollandia. Presumably, the Alfa sunroof has some strengthening in the roof that this one doesn't.
Theres no clunks or anything, just draughts through the top of the doors like someone is pulling at the seals. We going to drive the car over an uneven road sometime this week and listen for any noises, maybe it can be traced. I'm a bit paranoid about jacking a car with the doors open anyway.