The surname Jenkins isn't as rare in Macosquin as I thought. Good chance that Jenkins of Letterloan will be Presbyterian.
Macosquin Presbyterian Church (also known locally as Englishtown)
Nancy Jenkins, dau. of Archd. + Elizabeth, Camus, bapt. 9 Feb.1829 [moved to Letterloan- see below]
Mary, George, Peggy Anne + Nancy Jenkins, ch. of John + Letitia, Litterlone, bapt. 23 Feb.1829 [this is possibly the John in 1831 census]
Mary Jane + Robt John Jenkins, ch. of Nathanael + Bridget, Litterlone, bapt. 31 May 1831
James Jenkins, son of Nathanael + Bridget, Litterlone, bapt. 5 Mar.1834
John Jenkins, son of Archd + Elizabeth, Litterlone, bapt. 20 June 1834
Peggy + Nath Jenkins, ch. of Nathanael + Biddy, Litterlone, bapt. 25 Apr.1839
Clarke Jenkins, son of James Jenkins + Liza Jenkins, bapt. 20 Nov.1885