My name is Patrick Duffy (using my mother's account).
I seen your post regarding you're grandfather Laurence Duffy of Monaghan. I have recently start completing parts of my family tree (it's slowly becoming an obsession) and have I found that the Duffy's in my family also come from Monaghan. My father Laurence Duffy (get use to this name) moved to England in the 1960s, this after his own father (my grandfather -also Laurence Duffy) was killed when a trench wall collapsed on him in Kilkelly, Co.Mayo 1959. My grandfather was originally from Monaghan, born in a village called Drumhirk in 1914 (one of six children; Mary Ellen, Patrick, Eva, Nora, Laurence and Bridget) - he left Monaghan in the 1930s after the death of his father (my great-grandfather) who was also named Laurence Duffy. This Laurence was married to a Eva Conlon (also from Monaghan) in 1905 (give or take a year - I still need to get the marriage lines). In the 1901 Census, Laurence was 30 years of age...which means he would have been born around 1871. I have a photo of Laurence and Eva.
Now...this where you're thread interests me...
Laurence's (my Great-Grandfather) father was (you guessed it) also called Laurence (my Great-Great Grandfather) and we believe he came from and had a big family - I originally thought 17 children(not 21), and was married to a lady called named Anne (I found them on the census). Laurence was born around 1846. I also believe he was living in a vilage called tanderageebrae in Monaghan. I have very little else to say about this line of my family as the details are still to be confirmed, I may be completely wide of the mark in terms of your thread but thought I would share this with you.
Futhermore I have a photo of Laurence too (my great-great grandfather. Which was probably taken in the late 19th/early 20th century.
feel free to contact me on here or on my email: email@example.com