I drop this in just to keep the party going ...
The book "Six Days" by Brendan DuBois was published in UK by Little Brown at Bittehhouse, Lancaster Place, London, WC2E 7EN.
Brendan is an American and lives in a town near me. A local bookstore got cases of the books to sell locally where Brendan has a huge following. That's how I got my copy. It's a thriller and a walloping good read. I am sure the book is an "English" edition because inside front cover is an advert wherein the publishers say "If you don't enjoy "6 Days" we will refund your money." (then address as given above.)
For you UK folks the offer is good until October 31,2001. The price on front is - in pounds-9.99.

So, we have an American writer with a book first published in GB and as far as I could see there were no changes in any references.
The book is set in NH and Vermont. While on a camping trip two people enter a shelter in the NH mountains during the storm where the man, a former special forces agent, recognizes the place is something very sinister. Yum!