Having done some research myself on shipwrecks, it has become very apparent that very few sword parts from wrecks of ANY nationality survive. The Queen Anne's Revenge has yielded only one sword guard. The Whydah likewise is scant. The Atocha did have one rapier turn up, but it was a swept-hilt vs the cup-hilt I'm inquiring about. Having done some searches and learning about what survives these wrecks, it became apparent why few survive (other than the obvious corrosion of iron items).
So far, the blades recovered from these wrecks have been, as Jim pointed out, trade items in the hold. With underwater archaeology, it was become known that delicate items, such as wood-stocked guns, daggers, swords, cloth, etc, that has survived had been stored in the hold. When many of these ships sunk, the hold was rapidly buried under the sand, with many of the said artifacts protected. Arms that would have been worn by the crew were not so protected. Yes, I know most crews didn't go walking around the ship armed, but they would have been readily available (at a weapons station on deck, mounted to a mast, in a storage barrel for boarders, etc. Likewise, surviving members who were so armed would have escaped with their weapons (survival after a shipwreck on a strange coast would have depended on it). Soooo...perhaps we'll never be sure if the Spanish and Portuguese carried these sword types to sea.
