'Ranger, old pal, you should not miss Sharps when you're in London. It's in the basement of Cecil Sharp House. A good idea is to arrive in the early afternoon, spend time in the library, go out for dinner and come back for the folk club. At least one of the regulars there, Gerry Milne, is very keen on maritime songs.
The Ibis hotels are decent, modern and not expensive places to stay. There are a few around London, including one in Greenwich. www.ibishotel.com is the address.
Check into train travel in advance. In addition to Virgin and other long distance carriers, there are often special fares on regional carriers. You have to poke around a little bit but you can find something.
A trip to Liverpool could be very worthwhile. If that's a possibility, please give me a call and we can talk about it.
Thanks again for taking care of the wife.
All the best,
Dan