I don't know about any of the weights, but you say they have all been checked twice. Please make sure you have enough payload capacity for the total weight of your family of 7, plus the weight of the hitch assembly, plus any cargo in the truck, plus the tongue weight. That is one long TT so I hope you have some towing experience. There are certainly campsites in commercial campgrounds and even in some state parks that will accomodate 39'. I don't think I would do it, but if you do I wish you good luck.
