Big problems with 5 year old Fleetwood

We have just had the 5 year service on our 2007 Fleetwood Meridien.  We use a mobile service guy who is registered as an Approved Workshop and I asked him to look at the front windows as we have been getting some rain in especially when driving in poor weather.  It turns out that the windows are distorted to such an extent that they won't seal properly against the rubber, and in one case you can actually put your hand through the gap!!  Bearing in mind that Fleetwood have gone bust and the supplying dealer likewise, I don't appear to have any recourse to anyone, and I'm going to have to shell out for new windows.  From trawling the web, it seems that there have been loads of problems across all the caravan marques with with these Polyplastic windows from Holland, but it is only via the dealer or manafacturer that anyone has had any success in getting replacements.  I have an after-market "Gold Cover" warranty from MB&G which conveniently excludes windows.

To make matters worse, the service damp test picked up 43% damp in one of the front lockers, which means we need full repair involving stripping out wallboards etc.  I am hoping that the warranty is going to cover that, although my initial conversation with them suggests they will look for ways to avoid paying if they can.

Does anyone know any good repairers who can handle this sort of work in the west London/Surrey type area.  I am in Ashford, Middx.  I spoke to probably the largest dealer with an Approved Workshop in the area (in Gomshall), and they want to charge me £66 for a damp test before they will consider whether or not to give an estimate for the repair.  No thanks!