Hi,
I couldn't find ANY Crawfords in my transcriptions for 1861 or 1871 but found 1 for 1851 which is also on freecen. 
http://www.freecen.org.uk/cgi/search.plPiece: SCT1851/113 Place: North Uist -Inverness-shire Enumeration District: 1
Civil Parish: N Uist Ecclesiastical Parish, Village or Island: Trumisgary
Folio: 91 Page: 4 Schedule: 15
Address: Maloglet
    Surname   First name(s)   Rel   Status   Sex   Age   Occupation   Where Born   Remarks   
    MACPHAIL   Ephumia   Head   W   F   78   Cotter    Inverness-shire - North Uist        
    MACPHAIL   Catherine   Dau   U   F   28       Inverness-shire - North Uist        
    CRAWFORD   Archibald   Grnson   U   M   17   Ag Lab    Inverness-shire - North Uist  
This may be him prior to marriage? 
There are quite a few on S/Uist 
Anne Marie
P.S. You may be better opening a new thread too for your query for more response where people will see the names first off rather than on here mixed in with others?