Sorry you had trouble. The seller did mention leaks and he had repaired it, that should have been a big red flag.
You said: "i went inside the trailer and lifted up the cushions for the dinette and saw that the new floor he had put down was lifted... as soon as i touched it i knew the wood was rotted...."
Had you done that BEFORE you made the purchase, certainly things would have been different.
You said:"i bought it and its now mine..."
In most states if there is no specific mention of a warranty, the courts have found that it is then assumed "as is."
I think you really don't have any recourse against the seller.
Good luck.