I too have relatives there. Mine is Charles Henderson of the Farm House, Glack. This piece from Ancestry.co.uk forum notes that they often mixed up the Parish in the census. Also, Balwherne is aka (Balwherene, Balquharn) and neither it nor Glack exist today. The correct parish is Auchtergaven.
Here is a list I located of all the people there in mid 1800's (
http://archive.org/stream/perthshiredire188990dire/perthshiredire188990dire_djvu.txt )
PARISH OF AUCHTERGAVEN-.
Allan, Francis, (r«p. of) N. Bams
Allen, Robert, New Ardonchie
Allan, Wm. , Pitsundry
Anderson, Hen. (rep, of), Burnside
Black, Robert, Upper Obnie
Butter, James and Donald, East
Blelock
Chalmers, James, Rashieley
Chalmers, James, Shielhill
Chalmers, John, Nether Blelock
Chalmers, John, Westwood
Chalmers, Peter, Logiebride hill
Chalmers, John, Little Tullybelton
Do^^•, John, Belston
Duff, James, Westerton
Dunn, James, Tullybelton
Dunn, Wm., Balwharn
Eraser, James, Jackstone
Gorrie, Wm. & Janet, Kinglands
Henderson, Charles, Glack
Keiller, Alexander, Loak mill
My Grandfathers Grandfather is Charles Henderson.
_____________________________
http://boards.ancestry.ca/localities.britisles.scotland.per.general/5583.1/mb.ashxHi
Depending on where these hamlets like Glack and Balwhern were situated, regarding census returns, the enumerator could easily mistake one parish from another.
However, on the 1881 census in Methven
Dwelling: Farm House Glack
Census Place: Methven, Perth, Scotland
Marr Age Sex Birthplace
Charles HENDERSON M 48 M Kirkcaldy, Fife, Scotland
Rel: Head
Occ: Farmer Of 54 Acres Arable ((Employing 1 Boy 1 Girl))
Marjory HENDERSON M 50 F Methven, Perth, Scotland
Rel: Wife
Catharine HENDERSON U 20 F Methven, Perth, Scotland
Rel: Daughter
Occ: Farmers Daughter
Isabella HENDERSON U 18 F Methven, Perth, Scotland
Rel: Daughter
Occ: Farmers Daughter
Robert HENDERSON 16 M Methven, Perth, Scotland
Rel: Son
Occ: Farmers Son
Marjory HENDERSON 13 F Methven, Perth, Scotland
Rel: Daughter
Occ: Farmers Daughter
Jessie Jane HENDERSON 6 m F Methven, Perth, Scotland
Rel: Niece