I'm just now getting a chance to read all the messages. Lucky for you, I used to be a legal secretary in the UK. You are facing some pretty complicated international legal issues here. My advice to you would be to first contact the US Justice Department, explain your situation and see how far you get from there. Second, contact a lawyer in the UK (I might be able to come up with some suggestions althought it's been a while!). You will be eligible for Green Form Legal Aid which will cover an initial consultation with a UK solicitor (translation: free legal advice!). You can also contact the Law Society in the UK (http://www.lawsociety.org.uk/choosingandusing/findasolicitor.law) for referrals to solicitors that specialize in your type of situation. I can't think off the top of my head, but there is some convention or treaty that protects individuals from such theft.
Well, here's a start. Good luck to you and I'll wish for you an amiable outcome.