To answer CP's question - er the ground, the instrument panel, the windscreen frame, the canopy hoop etc.....
I'm amazed how much polarised debate my question has presented. I did my conversion with a well known 'Mr Chipmunk' at a west of London airfield. In the cafe / bar before and after flying he can be found wearing a smart shirt, cords and brogues but when it comes to flying his beloved Chipmunks its Nomex flying suit, gloves and leather flying boots always. Apparently having had an in-cockpit fire once is his rationale for this level of protection but each to his own I guess.
I also fly a more normal motor glider and gliders and other than the practical advantages of the pockets in a grow bag, I usually fly those in shorts and trainers.