Not wishing to carry this on but is not the answer both are right?
As regards 'sold as seen', as a private seller selling to a private buyer, and if the van was not as described, then it would need to be proven the seller was at least likely to be aware. Difficult to say the least?
(Genuine private that is and not the type who sell regularly on ebay, no idea where one would stand there?)
As I see it though, a trade seller would need to prove he was not aware, very difficult for him I think and there I've always thought lies the difference.
(Genuine trade stopped using the term several years ago, often preferring to sell on to another trader)