Thank you......yes could well be another ship. great thought.
Well he was sentenced in 1839 and received 7 years , He doesn't appear on 1841 census ( that I have found....his wife and children do) but he is back at home by 1851....so that would have been after his sentence anyway; and while I know that it would have been difficult to get home had he been transported it is not beyond possibility, though perhaps it does suggest he didn't get transported.
Thanks for the interesting thoughts, its an are of genealogy I have not encountered much.