Hello Marie,
Appreciate it some time since you were inquiring about Percival Blissett. there was a Percival Blissett lived at 21 Park Avenue in the Sandymount area of Dublin in 1911 census. He's listed as 37 years of age and married to Elizabeth, no children. They were recorded as being English nationals. There is a good possibilty that they fostered a family of children who had lost their father from T.B. and their mother had mental issues. That family was called Knight and one of them Alfie has received some fame as the 9 year old boy who wrote to Lord Kitchener in 1914 requesting that he join the army as a despatch rider. The letter is on display in the Imperial War museum London. Needless to say he was turned down for enlisting. The two sets of facts match each other.
Hope this helps you belatedly with your enquiries.
Regards
John