Harry Firstbrook married Mary E Darley (nee Brown) from what Helen Fosbrook has advised a second marraige for both people.
As far as I am aware there was no children descended directly from this marriage

However Mary's daughter from her first marriage Edith had a son Harry Hampson (my father) who was taught by a lecturer at what was Oldham Technical College by the name of Walter Firstbrook He was lecturing on the subject of Radio & Television (electronics) around 1962-1965

My father queried his name to discover that he was a nephew of Harry Firstbrook.