I just wanted to add, somewhat belatedly, that whenever I help somebody with a visa, part of the show is a so-called "letter of introduction" to a bank, like HSBC or Abbey.
It's just a letter from me to the bank manager that explains a little bit about the person's background and that I have seen all their details. Sometimes it works like gold, and sometimes it doesn't. About 70-30. But in the cases where it works, it works well. Granted, most of the people who need such a letter are newly arriving from LDC's, but there's nothing to prevent an American from having one.