Hi, I have never heard of Back Brook. The only places with "Brook" that I know are Donnybrook On the Sth side+Bonnybrook on the Nrth side of Dublin. I will ask around though. It could be a little place at the back of Donnybrook? If I had something else to go on, ie, the name of a Church/Chapel where a ceremony took place, I'd be able to locate it through the Parish. Maggie