There is a thin rigid plastic part that lies immediately above the flush handle on my loo (white plastic maybe 1.5mm thick) that has become brittle with age and now lost some bits leaving an uneven sharp edge. Probably this is out of the way of fingers but perhaps someone can help. Is it possible to swivel the bowl section so that it can be lifted off (bayonet style?) so that I can replace the part? I've had a good look at the 'exploded' parts diagrams on the Thetford website but cannot see this as a replacement anyway, so the job might need a bit of 'Heath Robinson' effect to repair!