In the 1911 Census, Henry is shown living on his own in Ballycanew, age 33, CoI, born Wexford. His occupation is Poultry Farmer.
However, the 1901 Census lists a Henry at Main Street North, Wexford Town, age 23, CoI, born Wexford. His occupation is Draper's Assistant.
There are a good few Hills mentioned in the 1901 Census, many living in Balloughter in North Wexford. It should be possible to locate the birth of Henry, who appears to have been born around 1878 in Wexford.
Is this your Grandfather - or did this Henry have a son Henry, after marrying? If you think Henry had a shop in Ballycanew between 1940-1967 - he must have been of advanced years when he opened the shop, as in 1967 he would have been c. 89!
Cheers