Hi Jen,
It looks like we have a few ancestors in common. I'm new at this, but I believe Patrick Long/Laing also went by the name Peter Long/Laing and his wife Mary Horan also went by the surname Horne/Horn.
On Mary's death record, it says she was the widow of "Peter Long" and her parents are listed as "Michael Horne" and "Ann Horne, maiden surname Dillen." The death record was signed by their son "Daniel Long" who was born in Carnock, Fife in 1859.
My records indicate that both Peter & Mary died in the 1890's in Lochee, Angus, Scotland (Peter in 1891 and Mary in 1897). I have the records along with some other info regarding Peter if you would like.
Let me know if this info sounds accurate to you because I am a bit thrown off by all the name variations. Hopefully it makes sense and we can compare notes. We could also compare our findings on the Hopper/McGowan/McQueen family as I have some of their records as well.
Thanks