I have absolutely no experience with what it might take to tour England. I saw Roscoe at the King of the Blues competition and might get to see him in Memphis if I end up going this year. What he is doing is compiling some press for whatever his next step may be.
When you posted this I remembered the name but not how I knew it. Had to Google it. Top of the results was the announcement and footage of his performance. I remembered then. Several Youtubes and then his Facebook page came up. I clicked on that link and it looked like his personal page. No band page I guess. He did have a Youtube channel and watched a bit of it.
I guess my point is you have to have something to sell in order to book. Does he have an EPK if not he needs to. He needs a website. Myspace is no longer acceptable and Facebook is just part of a web presence as is Youtube but you need it all. Winning the King of the Blues is a great first step along the path and IBC would be as well but both of those are a niche' that sells anemically in the US and I'm guessing the UK may have not even heard of the Guitar Center Contest.
I had a recent winner at a club I book a few months ago and he was a good player but his show was not all that impressive. His vocals were horrible. His band had rock star look but he had no hook. Sorry for the bad poetry, the guy booking him did the show for $200 as he was routing for NAMM and I lost money. I'll never book the guy again although I have lost more money I have enjoyed some damn good shows that nobody else knew about.
Really this is a chicken or the egg thing. Does he try to break in Europe or the US. Of course there are many artists that do one and not the other just look at Beth Hart who couldn't get arrested here but in Amsterdam and parts of Europe she was huge. He needs to get something going here first is what I'm saying. If he wins in Memphis the best thing he will get is an offer from an agent and some festivals if he doesn't and he wants to try the UK he needs to get some interest over there and how you do that is the real question.
I say he needs to work on his web presence and hit the road regionally first and work further and further out by taking gigs for gas money and selling a little merch along the way.
Hope this helps. Good luck.