Hi Barbara! I've found a David McKay, who was the son of Mary Noble and Charles McKay, born 2 Jul 1795, and baptized 27 July 1795 in Saint Cuthberts, Edinburgh, Midlothian, Scotland.
As for any other source which directly links back to this one...I can't seem to find any. There are 3 different 1841 census listings for a David McKay who was born in 1795...but each of them was still alive in 1841.
There is this one, who died in Aberdeen in 1840, but no way to connect this information with any other found David McKay (https://www.deceasedonline.com/servlet/GSDOSearch?DetsView=Summary&src=ext&fileid=1669240
You're going to need more information in order to figure this one out. Family members' names would be a great place to start.
Good luck with it!