Thanks John, my van is a '98 Sterling Europa 2 berth and like you I'm sure the washroom at least will be a bit brighter!Hi Ron - your roof lights are obviously different to mine (on a 1998 Abbey) In my case the head of the screws were visible and they had a sealing washer under the head. All that I can say is that cleaning was really worthwhile and has made a big difference inside the van. Interesting to hear the answer to your query.
John