Despite the fact there were hundreds of bricks lying around Bryn Brickworks when visited in October 2014, I struggled to find one with "Bryn" incised. Eventually I found two in a stream some distance from the kiln, this is the better one but it's not a good example.
Bryn Brickworks 1921
Bryn Brickworks (disused) 1947
Bryn Brickworks October 2014 - courtesy of Neil Holman