Another total long shot BUT
You know the way there is a Matthew Comerford marrying Anne Cullen in 1876 in Dublin City.
After the children were born, so I'm hoping that it's the same couple BUT for some reason they didn't marry earlier.
So, back to the Butler Occupation
The Matthew that got married in 1876 got married from 23 Kildare Street, Dublin.
Point One ~ Butlers were transient at times and moved to where their employers lived at the time.
So, 23 Kildare Street is quite a 'fancy pants' address ~ defo one that would require a butler !
If you google it you will see a newer building on the spot but they were all important buildings in the area as far back as I know of !
Tara