Illusive people

What records are we struggling to find?
There is a lot we have to put up here yet .. lots and lots and lots.
but there must be searches we are all doing that have just proven fruitless so far

Jessie Campbell - birth about July 1850 (she is 8 months old in the 1851 census at Auchindrain)
Malcolm Munro 1826 - 1892 - 1841 census - not with family in Cross Houses