This has to be a wind up!! Did you really pay 3K for something so naughty the vet couldn't even vet it?!
you say you've been practising NH techniques...that would suggest you've had the horse a while, in which case your management is more likely to have caused the laminitis not the dealer.
This has to be a wind up. Surely if a vet couldn't get near a horse to vet it they would advise a prospective purchaser not to touch it with the proverbiable barge pole!