I see this thread has come back to life, so I will just add something on my own family link to Percy Place. Interested in any info others may have...
My mother was born at Percy Place in 1937 and given up for adoption. K Dalton is named as informant on the birth certificate. Mother's name given as Bridget Lavin, from Ballyhaunis according to the baptismal certificate from St Mary's Haddington Road.
It gets a bit complicated after that because she was initially given up in a rather informal fostering arrangement to one Mary Murphy (when only a few months old it would seem) who took her to Liverpool. There is more of a story behind Miss Murphy (she had had other foster children), but the war years were clearly difficult and she gave up the child a few years later for a formal adoption through a Catholic adoption society in Liverpool. We managed to get hold of documents and letters relating to that second placement, but the initial fostering appears undocumented (Tulsa have not come up with anything).
Ancestry DNA has not matched anything closer than 2nd cousin once removed, but on that basis (along with a lot of other matches), one side links to Kennys of Wexford and Wicklow. There are some Lavin matches, but nothing closer than 4th-6th cousin, so that could just be a Co Mayo ancestor a long way back. Nothing yet to tell me anything about Bridget (if those details are correct!).
Steve