Roy,
I'm very interested in your search for Alexander and Jane (Noble) Smith. I found their marriage record at familysearch.org:
ALEXANDER SMITH
Spouse: JANE NOBLE
Marriage: 28 MAY 1842 Carrington, Midlothian, Scotland
Source: Parish registers, 1653-1858 Church of Scotland, Parish Church of Carrington
I also found their family listed as the following:
Alexander Smith
Birth: 1823 Of, Newbattle, Midlothian, Scotland
Wife
Jane Noble
Birth: 1821 Of, Newbattle, Midlothian, Scotland
Children
1. Robert Smith
Male
Birth: 17 JAN 1844 Newbattle, Midlothian, Scotland
2. James Smith
Male
Birth: 26 FEB 1846 Lasswade, Midlothian, Scotland
3. Emily Smith
Female
Birth: 19 APR 1848 Lasswade, Midlothian, Scotland
4. Christina Hannah Smith
Female
Birth: 18 MAY 1850 Lasswade, Midlothian, Scotland
5. George Smith
Male
Birth: 31 MAY 1852 Lasswade, Midlothian, Scotland
My husband's great grandfather, George Smith, was born in Scotland May 31, 1852, so I thought this might be his family. He came to America in 1887 or 1888, according to census information, but I haven't found his immigration record yet. He married Catherine Barr, who I believe came from the same area of Scotland, but I don't know anything about her family either. George and Catherine's first child was named Alexander, which also seems to fit. If you have found any more information on this family, I would love to hear from you.