There isn't a "Rambo" line of bedlingtons.
Sure, he crops up in enough pedigrees, but the dog was not the product of carefull worker to worker breeding, and indeed all his litter mates never amounted to much. But with good careful handling and entering, the dog worked regularly below ground and above.
To say he was a "KC simplifies it a bit too much, there are very different types of Bedlingtons out there, registered or otherwise.