I don't often check back in here but it's definitely very interesting about the alternative spellings. I have found a few references to who I believe are the people I'm looking for in Mayo and the Treston spelling was used. There were apparently some Huberts in that family as well, so it still looks like they're connected somehow, and there was at least some sort of Dublin connection with at least one member of the family serving in the Dublin police before returning to Mayo. I also believe the Adelia I am looking for may have also been known as Bridget. I don't know why this was the case, but I found a baptism record for an O'Reilly child where the parents were Laurence O'Reilly and Bridget Treston, and another where she is written as Bedilia Treston (which at least sounds like Adelia!). It did trigger something to me, though, my late grandmother used to refer to the other Adelia as Bridget and I never understood why. If her mother was also an Adelia known as Bridget, that would make at least a little bit of sense.