Hi ancestry.co.uk have records of burials there up to 1856, St Giles burnt down and a new St Giles was bult in 1844, St George Camberwell did have burials in the late 1800s but there is a gap from the 1850s up to 1899. The civic cemetary that covers Camberwell is Nunhead:
http://en.wikipedia.org/wiki/Nunhead_Cemetery
If you are not an ancestry subscriber I could look up the burial registers or Camberwell or you could contact the Nunhead cemetary.
East Surrey Family History Society have some indexes for Camberwell but they do not appear to hold an index to the Monumental Insciprions there.
This history of the Parish confirms there were no MIs recorded:
http://www.stgilescam...=blog&id=54&Itemid=69
If the husband was buried with the wife in the churchyard then there wil be an entry in the burial book, which does not mean the funeral was held at the Church, and by the same token, if he was buried in a civic cemetary, that does not mean his funeral was not heald at the church, and the church records should show a record of the funeral as opposed to a burial. This is an area people often confuse.