Yes, peoples names and place names in Ireland were spelled differently all the time. And sometimes still are. Its to do with literacy but also variant ways of anglicising Irish words. And there was an indifference to consistent spelling then too. Having a precise spelling is very much a 20th century phenomenon to meet modern requirements with officialdom.
In 1899, the Rev Smith reviewed the early records of Antrim 1st Presbyterian church (covering the years 1674 to c 1736) here in Ireland. He noted: Even the same word is not always spelled alike by the same hand. Indeed spelling with most of the recording officials (and they must have been fairly numerous) was a matter of the most sublime indifference. The name William, for instance, is spelled 3 different ways in as many lines; while Donegore, a neighbouring parish, is spelled 10 different ways; but these extend over a good number of years. Many families names are spelled phonetically, while others are given in the most round-about fashion.
Spelling varies.
