Hi aghadowey, that was the record set I was searching (thanks for the link).
So, you're suggesting it's neither of those places?
When I search on Killucan, it brings me east of Mullingar. Is that the place you consider these records to be from? Peter died in 1885 in Widnes, which was then in Lancashire (now Cheshire I think). On all census from 1841 when he married his wife Roseanna Murphy in Glasgow, Scotland, his birthplace is just indexed as 'Ireland'.
As always, I appreciate your help,
Kit