Peader Kearney -

[Abhanliath]

Thank you, @myluck - I'd seen that entry for John Kearney but didn't think it was the right one, because the Crescent in Clontarf, home to Bram Stoker, was a rather classy address… and was he an insurance collector? The father's trade given on the marriage registration of Peadar Kearney and Eva Flanagan is unreadable (by me anyway). It might say 'grocer' - and the Dictionary of Irish Biography does describe Kearney pater as "grocer and businessman".
The house in Cabra is the notorious North Dublin Union (if you go into the "Household Return" below the census it gives you more information).
Good spot on the Keanney mistranscription - the census returns were transcribed in India, so sometimes the handwriting wasn't familiar to the transcribers.

[Abhanliath]

Oh, by the way, 42 Upper Sackville Street, where Peadar Kearney was living and working in 1901, is listed as the Catholic Commercial Club in the 1904 Thom's Directory, at which time it was being run by John J Gartlan and William Hogg, hon secs.

[myluck!]

7 Crescent Place in Clontarf was a small cottage that is still standing

On the 1901 census there is a family named McGuinness living on this road
Patrick (50) and his wife Anne (nee Byrne from birth records) (60) both born Co Meath with five children aged between 17 and 33 all born Dublin.
There is a marriage in Kells, Co Meath on Oct 16 1865 between a Patrick Maginnis and Anne Byrne but unfortunately their parents are not listed.

These may have been in-laws of John Kearney and the address from which he was admitted to hospital.

I have restarted my search! - thank you