Hi
Doing an IGI search with parents David Gibson and mother Isabella produces four baptisms at the Golden Square Presbyterian or Scotch Church, for:
John Gibson in 1807 ,Alison Gibson in 1809, David Gibson 1811 and Robert Gibson 1815.
As is common in churches in England, the mother's surname is not given, but it looks highly likely that John 1807 is your ggg grandfather.
If you search on Scotlandspeople statutory deaths, entering 'Elizabeth Gibson' and maiden surname Miller, between 1855 and 1875, one match is found. (Sorry, I don't have any Scotlandspeople credits at the moment.) You will be able to see Elizabeth's death certificate, and statutory death certificates in Scotland give the names of the parents of the deceased, including the mother's maiden name.
I can't find a match for a death of John Gibson with mother's surname Renton, but that either means he died before 1855, or he died in England.
regards,
Lesley