There was also an Andrew Todd in the Ballykelly area. The Court Minute Books for the Fishmongers Estate records that on 28 October 1829 a weekly pension of 1 shilling 6 pence was granted to Andrew Todd (p. 121 of vol. 14). I am not sure who he was.
In case you did not have this, there were 30 families in the 1831 census of Toneduff giving a total of 170 inhabitants of which 18 were servants. The heads of households were Samuel McCoomb, James Riddles, John Riddles, David Riddles, Robert Riddles, John McGlinchy, Thomas Brown, Elizabeth Kincade, James Laughlin, James Nixon, Robert Miller, James McLaughlin, John Deens, John Hamilton, Andrew Nixon, Thomas Nixon, Thomas Mitchell, Mary Mitchell, Rev. James Allison, William Gardner senior, Thomas Todd, James McTeely, Charles McCarter, William Gardner junior, William Hamilton, Christy Ruth, Adam Todd, Oliver Scott, James Molloy, and Thomas Ruth.