I am also very interested on the Kemmet(t), Kimmet(t), Kemmit(t), Kimmit(t) surnames. My roots are in Co Sligo where the name was widespread in the 19th century. I have quite a lot of individuals in this county but also in the neighbouring Co Roscommon. I have a Michel Kemmet, born 22 Oct 1834 in Roman Catholic, Taunagh, Sligo, Ireland. His parents were Thomas Kemmet and Catherine Coggins (alos Coggan). I also have James Kemmit, born 22 Aug 1833 in the same place (parents : James KEMMIT & Margaret MILMO). Both could be the people you have listed. Finally, I have been in contact with a gggrandson of Betsy & Martin Tansy. He told me Betsy was born in Sligo in 1830.