Oh, now this is interesting. Although listed as Harold Howell on the census records, his birth and baptism record lists his name as Thomas Harold Howell, father Walter Thomas Howell, mother Sarah Jane.
England Select Births and Christenings 1538-1975 for Yorkshire West Riding, York, England
Birth Date: 10 Apr 1891
Baptism Date: 10 May 1891
Reference FHL Film #1542265
As this thread is quite old now, you may already have resolved your questions, so I won't bother to go any further at this point. If you do need more information I would be willing to see what I can find.