Do you know that little back road, behind Robert price timber yard, D c, just below castell coch?
Going back about 45 years ago, my old man's mate, who lived in that little road, owned the father to my only terrier I owned from a pup, and he had brindle markings, and was probably the best physical specimen that I've personally seen of any terrier.
He was apparently well worked to ground, and was marked up, accordingly.
Bear in mind, I was 14, and my old man had no interest in working dogs!! Lol