Had a read back through the thread to refresh my memory.
To sum up so far-
Duncan Sinclair Darroch is born 31 Jan 1874 to Mary Darroch -
https://familysearch.org/pal:/MM9.1.1/XYBJ-95P A Mary Darroch marries a Hugh Dawson at Inverary 1878 (still to be confirmed on Scot People).
1881 Census -A Mary Dawson and Hugh Dawson are living at Lochgilphead with a 6 year old Duncan Dawson (son, but obviously born before above marriage)
1891 Census -Mary Dawson and Hugh Dawson are still in Lochgilphead with 2 boys Duncan Sinclair aged 8 and Robert Dawson aged 4. The boys are recorded as Under Guardianship.
1901 Census- Mary Dawson and Hugh Dawson at Lochgilphead with 2 adopted sons names as above aged 18 and 14.
1891- Census- A 17 year old Duncan Campbell is a farm servant at Dalchenna Farm
and per Dougs123 info-
1901 Census - Duncan Campbell at Renfrew
He marries Jean McNeill and gives his parents as Archibald Campbell (quarrier) and Mary Campbell maiden name Darroch.
We don't have the date or location of that marriage Dougs123. Could you post it please.

Just posted this to group info together,
Looby

Amended Census date as per Monica's next post