I am almost certain that these Prestons attended St George's Church of Ireland Church in Keenagh, Co Longford, Parish of Kilcommick. I think there may be some Preston graves at the church.
I think they had a farm at Clough, Keenagh, Co Longford which became Crooke's as I think Henry Crooke married a Preston lady and had a large family. . His son also Henry married Ruth Mills and had at least 5 children. Farm & house is still owned by the Crooke family today. One of the last remaining thatched farm houses in Co Longford, it still stands on the Keenagh - Ballymahon road.As a child my family visited the house to visit Granny Crooke - my Aunt was Daphne Crooke married to my mother's brother - Joseph Bigley, Daphne was born there and is the last surviving member of that generation of her family. Granny Crooke was Ruth Mills before she married & lived to be 99, a lovely warm lady in the best tradition of Irish farmers wives..
Much of the land around Keenagh in the 19th & early 20th century was part of the King Harmon Estate based at Newcastle House, Ballymahon, so the Prestons were probably tenants of that estate.
There was also the Kingston (otherwise McCloughry) family at Mosstown House, Keenagh, Co Longford who held a considerable independent estate near the village of Keenagh. Keenagh Village origins was as a settlement for the Mosstown Estate workers with many people employed in the Mill at Mosstown.
RCB Library in Dublin would hold the Church records for births, marriages & details in Kilcommick Parish, Diosese of Ardagh, Co Longford