Oh dear
It all looked as if it might tie up, but it doesn't.
I see that Joseph Watson and Mary Ann Steell were married in 1835, before the start of civil registration in England, so presumably the marriage record doesn't give Joseph's father's name and occupation?
And I don't see a marriage date for James Christie and Helen Scott, but some of their family were born in the 1840s so it must have been before 1855 when civil registration started in Scotland, so it wouldn't have been much help anyway.
For the early census try
https://freecen1.freecen.org.uk/cgi/search.pl - Aberdeenshire is well covered, but Angus is patchy. However it does include the following:
1851 Census: 9 Reform Street, Montrose
James Christie Head Mar 31 Power loom starcher Aberdeen
Helen Christie Wife Mar 34 Glasgow
3 children
James Scott Brother-in-law 16 Baker apprentice Glasgow
Alexander Stewart Cousin 20 Baker journeyman Montrose
1841 Census: Market Street, Montrose
George Christie 40 Linen power loom weaver
Margaret Christie 35
James Christie 20 Linen power loom weaver
plus Christine, 15; John, 15; Margaret, 14; Andrew, 13; George, 11; David, 9; Alex, 7; William, 5.
Everyone born in Angus except James.
They match the family of George Christie and Margaret Cobb, who were married in Montrose in 1823 - which is after the birth of James.
1851 Census: 39 Market Street, Montrose
George Christie Head Mar 52 Overseer power looms Arbroath
Margaret Christie Wife Mar 47 Montrose
plus Andrew, 21; George, 19; David, 17; William M, 13, Mary Ann, 8; and Robert, 6. All born Montrose.
There's more detail in FreeCEN than I have included here.