I think we had a thread about the London's guns. I know that we had one about the illegal recovery of guns from the HMS London, and the arrest of some folks in Kent, England.
I only know of two guns (42-pdr & 12-pdr) that have so far been recovered from the HMS Victory wreck by Odyssey Marine Exploration, Inc., and those are now possessions of "The National Museum of the Royal Navy", but Odyssey also claims that at least two, and possibly up to six guns have been removed from the site by looters, so it's altogether possible that there are cannon from the Victory being bought and sold.