I Have a Seitz roof light I think it may be call a skyview it's the big panoramic curved Auto-trail jobbie. The fixing scews for the internal surround go through what looks like a white plastic tophat and then is blanked off with a circular plastic disc once the screw is tightened. Does anyone know where I can get some? The problem is one of the screws has sheared off so I need to take the surround of and the only way to get the blanks out is to dig them out which is going to damage them. Been all over the Internet and can't find any.