Lisa, it was nice talking with you on Chat last night. Yet another suggestion: if you have the chance, do not miss the London Silver Vaults located in the Old Bailey neighborhood. Everything old and new in silver that you can possibly imagine. A huge place open to the public. I bought a bracelet and a serving spoon made in the 1800's. The latter has outlasted some of my newer spoons bought here.
Also, the Old Royal Observatory Greenich is an ineresting place to visit. You can get there on the Underground. You can probably find out about it from teh cruise line. If you can, it's wise to go with a tour group. Then you don't have to climb that awful hill like we did!