When my 1993 bessacarr was in for service the guy said the body had come away from the chassis and would cost around £1500 to repair.
How is the body fixed to the chassis? is there a diy solution
As far as I know they are bolted on.
But ask for a detailed estimate if they don't offer one go to a repairer who will.
Shop around is best but don't always think the cheapest is best.
Also who ever does it should issue a guarantee if they do a good job.
howtomendit.com for free repair help, information and advice.
Try fixfault.com to fix caravans/motorhomes.