Looked on Ancestry and a few trees on there - including your own too I think. I have tried Familysearch.org with no luck though there are a few Samuels with possible varied spelling of McClamance born in Scotland.
e.g
Name Samuel Macallum
Spouse's Name Catherine Quin
Event Date 03 Nov 1839
Event Place Middle Church,Paisley,Renfrew,Scotland
Lyn
Registration of Births, Marriages and Deaths began in Scotland on 1st January 1855.
I have had a couple of Scottish lines myself to follow and it was familysearch.org that gave me leads - however there are no positive leads I have found for this particular name.
Ancestry 1871 census - Name: Samuel Mccullum
[Samuel Mccallum]
Age: 58
Estimated Birth Year: abt 1813
Relationship: Head
Spouse's name : Mary Mccullum
Gender: Male
Where born: Ireland
Registration Number: 644/8
Registration district: Anderston
Civil Parish: Glasgow Barony
County: Lanarkshire
Address: 12 Pembroke St
Occupation: Brass Drasser
ED: 7
Household schedule number: 91
LINE: 11
Roll: CSSCT1871_136
Household Members:
Name Age
Samuel Mccullum 58
Mary Mccullum 46
John Campbell 30
Ann Campbell 24
John Campbell 11
Mary Campbell 5
1861 census - Ancestry only has basic index details for Scotland
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Name: Samuel Mccallum
Age: 48
Estimated Birth Year: abt 1813
Relationship: Head
Spouse's name : Mary Mccallum
Gender: Male
Where born: Ireland
Registration Number: 644/8
Registration district: Anderston
Civil Parish: Glasgow Barony
County: Lanarkshire
Address: 5 Whitehall Street
Occupation: Iron Dreper
ED: 17
Household schedule number: 84
LINE: 16
Roll: CSSCT1861_108
Household Members:
Name Age
Samuel Mccallum 48
Mary Mccallum 39
Thank you to everyone who took the time to look and to search. Sophia ia a real mystery and I am still searching.
Thanks Lyn for your suggestion but Sophia McCullum married in the same year as Sophia but in Lanarkshire and I know she married Reuben Brackenbury in Sheffield.
However I am thinking Sophia might have come from Ireland as Reuben was in the 1st battalion 16th (Bedfordshire) regiment of foot based in Newry Ireland from 1/4/1871 - 30/6/1871. he married Sophia 14/1/1872 and their daughter Georgina was born 1872 in 4th quarter.
On the 1881 census it says she comes from Glasgow, 1901 census from Scotland and 1911 census Sheffield.