Hi Stuart ... Season's Greetings to you too ...
I'm not related, although I have quite a number of Gourlay names in my files - but ...
Have you tried the OPRs at Scotland's People? If you have his parents' names there may just be something there - assuming they were from the Kilconquhar area. The old records from the kirk there are pretty good.
Ceres is a good starting point. I believe the oldest headstone in the kirk cemetery there is a Gourlay one.
The name was quite prevalent in the East Neuk fishing villages.
Maybe a visit to ScotlandsPeople in Edinburgh for a trawl through the Census registers could help you too. A laborious task, but worthwhile.
Regards
Chiad Fhear