[EXT] [Islay] Sinclairs plus Argyll Colony, N.Y.
In the Daybook of Daniel Campbell it says "The dissatisfaction among the Tacksmen and their families finally resulted in a large emigration of the younger men, their families and sometimes their servants, to New York Colony, organised by Captain Lachlan Campbell of Leorin" (page 21) which the index shows as being in Lower Kildalton parish . It also says that the "History of the Somonauk Presbyterian Church" has preserved the full sailing lists, plus a number of other documents, which shows what happened to most of the emigrants.
In the Passenger list of 1739, there is a Duncan McDougall & Janet Calder, his wife, John, Alexander, Ronald, Dugald, and Margaret, his 5 children. Then (and this is confusing) it adds "Dugald, Gilbert, Flory & Margaret his 3 Children". I'm not sure whose children these are supposed to be. Also on this passenger list is an Angus McDougall.
I hope this helps you get back further in your McDougall search into Kildalton parish. Just looking at the 1749 map of Islay by Stephen MacDougall, surveyor (Coincidence?) it shows Upper Lorin and Lower Lorin in Kaldalton.