Sometimes when you blow up a census, not literally you can see the spelling better. People reading them often made errors
in what they think they saw. How would you get Nathan out of Edward? Then on top of that people changed the spellings or someone changed the spelling for them. 20 years - you have staying power. You can contact the Clare genealogy office although it is commission work only. I asked for a quote
once from Wicklow and depending on how many generations the cost would of been 500Euro. I flew to Ireland for less than that as the exchange rate was higher than today.