If you Google - where is greenock in scotland - it gives the info
Greenock East was the registration district
You can download a copy of his birth cert from the Scotlands People website & use the same site to look for his parents marriage. Downloading their marriage cert will take you back another generation as it will give both sets of parents names
Downloading is via purchase of credits. You also need credits to download the 1911 image as it is only available on SP