Hi Nicca,
John Hammett was my great-great-great-granduncle. I am descended from his sister Jane. I have been dabbling in family history for years now and have a good bit of Hammett info if you are interested. The Hammetts were Church of Ireland as were the Dudleys, I am not sure about the Hanans, they may have been COI or RC. John was a shoemaker by profession like his father but sadly his first wife Dorothea died in the famine as did their two little daughters. He married again but it is a bit confusing as to if he married once more to Elizabeth Hanan in 1852 in Youghal, or if he did marry an Emily/Elizabeth Dudley as well, as he gives his wife Elizabeth's maiden name as Dudley on a later birth registration. But Elizabeth Hanan outlived John, so he didn't marry again after her. John and Elizabeth moved to London after the famine, and the family in Ireland lost touch with them. But John's son John and daughter Mary Eliza went on to have families of their own. We think he also had a son George who may have died of Smallpox in 1881.
How are you related to John?
All the best
Natasha