box - I must say that it has crossed my mind...
If I can work out the logistics of registering the Kirkhams over here, I'd bet that I could sell a handful of them in a heartbeat. The devil's in the detail, and the local transport inspectors and regional engineers are sticklers for the seemingly insignificant details.
When you see how easily replicas are engineered / complianced in states like Arizona, it almost makes you want to move over there to live. Then you remember the 50 degrees C temps over there during summer....