This thing hurts like a mule and easy to make. The millwall brick is basically a newspaper folded and rolled into a thick "brick." The tip is very hard, probably hard enough to breaks a man skull, easy to make. Just roll up an newspaper or magazine tightly. Fold it and wola, you have a perfect improvised weapon out of newspaper.
I made a few, one was a failure but the rest had the intended result, the paper being as hard as a brick.