I have not been able to pin down your Duncan in the Scottish census records, are you able to tell me where he was in the 1851 census.

I have noticed a (farm) called Kilchiaran close to Kilchoman. In the 1811 Tenants list there is a Duncan McLellan at Kilchiaran, phonetically this sounds like the placename in your email of 29th January.

I am not making any progress with my family, so any snippet might help me link up with any other snippet, one never knows.

Mike