I wrote to newton in Britian and inquired as to if they sold here in the states -they replied to get a quality type interior ask moss or victoria for what they called "Mark I " has anyone heard of that?
I know this is a Moss forum, but if you are looking for quality interior products, you may want to consult http://www.heritagetrim.com/
Not the cheapest solution, but they are "made to order"
http://www.prestigeautotrim.com/uk/mg_home.htm
I have seen a few cars with their product and I am always impressed with their stuff. Good price and reasonable ship time.