Help please - We have a Bürstner Harmony, t625, 2003, very low milage. We had a drip coming through one of the screws from the skylight on to the bed. It only started after my husband cleaned the roof with a new brush we got. We suspect it removed some worn sealant. We got it fixed immediately. The water ingress had run through to the bathroom ceiling, although it didn't have any leaks. It has left a small water mark, not that noticeable, but I know it is there. I am not sure what to use to remove/cover it. Can someone advise me please? Thanks in advance