From the 1901 census when Harry was 15, we can deduce that Harry was born in 1886.
'Bagnall Harry, 19 Stanley road' listed as private resident in directory
I was contacted by Irene Wilson who very kindly supplied her recollection:
My Grandfather was Harry Bagnall who originally lived on Stanley Road Wakefield. He died when I was quite young and his wife died before I was born. I can remember him when he got old he went to live in Oxford with his youngest daughter Norah. He came back to Wakefield to stay with his eldest daughter Gertrude Mary (my mother) at Albion Street Wakefield. I think this was about 1960 and it was always said that he came back to Yorkshire to die.
I seem to remember he had a brother who lived in York Street Wakefield. I think he was called Milton or something like that. (RB: This could perhaps be John Milton Bagnall)
I was always told as a child that Harry and his father built the public library in Wakefield and a school near the market. (RB: See Drury Lane Library)