I don't know the extent of the estate.
The 1875 Valuation Roll at
www.scotlandspeople.gov.uk list the Rev Angus Macdonald as proprietor of house and land at Knoydart, and Martin Macdonald as proprietor of a house etc at Airor, Knoydart.
Inverie is the only village in Knoydart. The VR lists a John Baird as proprietor of Inverie.
Knoydart is part of the parish of Glenelg, so that is where to look for any records of baptisms and marriages in Knoydart.