Hi Wiggy
Have another look at the 1841 family:
Dinnwoodie Mains, Applegarth (ref as before)
Johnstone
George, 24, farmer
Elisabeth, 48
David, 18
James, 17
Mary, 15
Agnes, 14
John, 13
George, 11
Robert, 9
William, 9
Francis, 7
Charles, 6
All born Dumfriesshire
and in 1851, this looks like your Charles A Johnstone and (brother) Robert:
Lodge Wynd, Annan
812 ED 3 Page 20
Margaret Rule, 37, shopkeeper, b. Annan
Robert Johnston, lodger, 19, writer- clerk, b. Applegarth
Charles A Johnston,lodger, 15, Druggist (apprentice), B. Applegarth
I think you should really study the 1841 family closely!
Gadget