The roof actually failed in the down position and needed manually lifting to the closed position. Trying to retract it only produces straining noises from the boot area. I've checked the one microswitch I can see after removing the trim cover at the back edge of the boot lid and given a spray of switch cleaner, looks OK. Looking inside the pump unit inside the spare wheel I noticed a small amount of oil in the polystyrene tray, but not enough to leak out of the drain hole in the boot floor. Looking at the image, I'm guessing that the clear plastic item on the left is the hydraulic fluid reservoir. This is half empty, which seems wrong to me as all of the hydraulic rams look to be either closed or pretty nearly closed. Should the reservoir be nearly full? Everything else looks OK.