Hi Marcie
Just catching up as I have been away and reading through your latest posts

This RCE entry that you have found, I am guessing has come from SP and is connected to a specific birth cert that you have viewed there for the birth of a John Laidlaw?
I am not sure if this RCE/birth cert has anything to do with your John

There is this entry on IGI which I think relates to the possible birth cert you have viewed (although you have quoted different names for parents):
JOHN LAIDLAW Birth: 17 NOV 1873 in Yarrow, Selkirk
Parents: JOHN LAIDLAW and JANET ANDERSON
The informant for the amendment referred to on the RCE shows as John Laidlaw, likely the father to son John, (1872 v. 1873 birth year).
I've been reading though this post again from the beginning. I think most of the info to be found has already been posted by Hume in the very early posts.
- William LAIDLAW and Margaret LAING, married in 1863, Leith
- Charles William LAIDLAW, born 1863, Leith looks to have been the only child born to them. He died at the age of six months from the death cert you have found
- Hume has included census entries for your John, with 'parents' from 1871 to 1891, birth year c. 1869 and born in Edinburgh in all censuses
- From all the info that Hume put together, does look likely that John was taken in very young and raised as the son of William and wife Margaret, who do not look to have had any more children apart from Charles in 1863
Not sure how you can establish who the actual birth parents were of your John unfortunately. John gave William and Margaret (Laing) as his parents on his marriage cert. and same parents were given on his death cert. Without knowing the name at least of his birth mother, you will not be able to establish his birth details. He may well not have know that William and Margaret were not his parents if he was raised by them from at least the age of two where he shows with them on the 1871 census.
Monica