Hi Starlet,
How lucky are you living in such a beautiful place!
You'll find all the census records have been transcribed and are available to view at Kirkwall Library and Archives in Junction Road, Kirkwall ~ just a short trip over on the ferry.
You are right the Houston's were there in 1881-1901 John Houston died in 1903 and is buried with his wife Mary Wilson in the graveyard at South Church, Shapinsay. Other Houston family members who lived at Barebraes are buried there too. You'll find them at the far end of the cemetery [furthest away from Balfour Village]
Laurina