Hi Lynn Ann
You don't say whether your grandfather had a middle name but
the only birth I could find that would tie in with the date of birth you gave for your grandfather was registered in Mar qtr 1914 V9c P488, in Barnsley Yorks, George W Rowbotham (mother's maiden name Waterfield).
With your grandmother's maiden name I could check the marriage registers around the time of the marriage date you gave to confirm which name your grandfather used on marriage.
Hope this is of some use