As this is a one-name study of Crennells, perhaps it does not matter too much if the Joughin bit is not quite right, but I would like to put the early Joughin bit straight, in case some one reading these messages gets off on the wrong track.
Matthew Mark Joughin's mother was indeed Ann, Ann Moore from the Mount Rule district of Braddan. Ann's husband was William Joughin, but he was born (or at least baptised) at Andreas in 1818. His parents were not those given by your uncle (and I seem to have an earlier version of his tree), but Daniel Joughin of Cranstal, Bride, and Catherine Kneale, who were married at Andreas in 1814. The names and dates your uncle offers are not shown in the IGI, nor the Braddan burial and MI transcripts. Would they come from a family tradition, remembered with difficulty?