I had a leak on my Bessecarr which Paul of Edgehill Motorhomes ( 01623 631837) in Mansfield effectively sealed. Him and Lee are completely trustworthy in my opinion and if you are near to the Midlands it well worth to give them a visit.I would suggest best course would be to get several quotes.
Ask them if the existing roof can be repaired (patched?), or indeed, is a new roof the only solution.
I'm a bit concerned that someone can quote £4.5K for the repair, but doesn't want to take the work on ?!
Paul is very experienced and although I have new mhome I would have no hesitation in going to him for advice.
I noticed that Paul was recommended by another Funster a week or so ago.
Robin