I think perhaps your David Murray was born too late to be related to my gt grandfather. My Murray family did not leave Dumfrieshire for Ayrshire until the early 1900's. My gt uncle, Robert Murray (b. 1879) was the only member of the family who could have carried on the family name and his son David was not born until 1909.

I know Murray is a fairly common in this part of Scotland, before I actually found my gt grandparents I stumbled across 2 other David Murrays, one from Cumnock and one from Kilmarnock.

Good luck with your research.