The Bishop's transcripts are a great resource but with gaps.
Mitford has a gap between July 1783 and March 1787 where George could be lurking and also another from March 1788 to March 1791 - another potential lurking place.
Meldon is the tiniest parish - used, I believe, only by the workers on the Meldon Estate. Still worth a look though - George's father could have been working there.
Christine