I am researching the Gibney family, and am fairly confident they came from Termonmaguirk.
I base this on a combination of an 1846 marriage record for James Gibney and Margaret Mains, followed by a review of Tithe Applotment information (1825).
Searching for Termonmaguirk, and was pleased to find your posting, especially since we came to the same conclusion independently.
Marriage record: "Ireland, Civil Registration Indexes, 1845-1958," index, FamilySearch (https://familysearch.org/pal:/MM9.1.1/FTBV-G32 : accessed 14 Sep 2013), James Gibboney, 1846; citing vol. 9, p. 425, General Registry, Custom House, Dublin, Ireland; FHL microfilm 101241.
Please feel free to contact me away from the message board, if you'd like to compare details.