T.H.Jacques elluded me for quite a while, even though the clue had been there all along. It was another entry in the 1916 Kelly directory for Leicestershire which I had missed. He was on CWGC but I just hadn't put two and two together.

Please see this recent thread:

That precious clue was that his father was the manager "National Brick Co." Heather, Ashby-de-la-Zouch, at the time.