Getting to the bottom of the various Christopher Todds may open up leads, starting with the 3 in the PRONI Will Calendars Index.
1. The Christopher Todd who died on 17 December 1928 was the one I posted at replies #14 and #15 who married Isobella McGowan in 1864, then a Margaret Elizabeth Harvey in 1917 (she also has an entry in the PRONI Will Calendars Index). This Christopher's parents were William (a farmer) and Eliza Todd and his birth based on census information and death record reported age was
c. 1842-44.
2. The second Christopher Todd who died on 11 May 1940 had a reported death age of 60 and was possibly the one born on
2 December 1881 as the son of Robert and Agnes Todd:
http://www.census.nationalarchives.ie/pages/1901/Down/Blaris/Ballymullan/1239468/http://www.census.nationalarchives.ie/pages/1911/Down/Blaris/Ballymullen/248586/Bachelor Robert Todd, a farmer living in Ballymullan (Blaris civil parish) married spinster Agnes Todd living in nearby Clogher (Hillsborough civil parish) on 15 March 1870, his father was called Christopher Todd, a farmer (yet another Christopher Todd), hers was Samuel Todd, a farmer.
3. The third Christopher Todd who died on 7 May 1905 is one I've yet found little about, or indeed about his brother William Leck Todd, other than the 1901 census return I posted at reply #11, but his brother William was still with the Pedlows in 1911:
http://www.census.nationalarchives.ie/pages/1911/Antrim/Duncairn/Limestone_Road/141442/And William's Wills Calendar index entry doesn't provide any obvious leads:
Todd William Leck of 75 Limestone Road Belfast retired warehouseman died 25 April 1932 Probate Belfast 17 June to Philip Brady cashier. Effects £607 0s. 3d. Again based on census and death record reported age, this Christopher Todd was born
c. 1835-36 and his brother William Leck Todd was born
c. 1851-52.