Shouldn’t stolen property if found be returned to the original owners? This is surely property that was originally taken from the inhabitants of Central and South America. Now two greedy former colonial powers are going to fight over it?
The whole point of salvage law is to prevent these squabbles over ‘original’ and ‘rightful’ owners. “Finders Keepers” is short and sweet, if you can get it out of the drink it’s yours.
Since you live in Florida I know you'll be sorry to to know that I'm giving it back to the Indians, from which the Spanish stole it from.