I vacation on Cape Cod, so I've been to the Whydah museum many times. Well worth the trip if you are in the area. So much more than what they showed on air.
The cannon barrel, which contains gem stones, has been in an electrified solution for several years. As of this past September, it is drying, and they are removing encrustation. Once the cork plug is removed, they are hoping to be able to "pour" the contents out to determine the value.
I thought the show was very good, and followed the local legends. I'd like to see it again, if it is rebroadcast. If not, I'll have to find the dvd from the network.