Hi,
You're very welcome. I would be very careful just using the index. John may well have been born in Leake but there are many records that have not yet been transcribed, so he could easily have been born somewhere entirely different.
Perhaps trying to trace what happened to John's sisters may yield some clues. If you're very lucky and can find marriages and baptisms of children for them somewhere in Yorkshire that has Dade records that would give a very good lead on the family.
It might also be worth trying to find any records for his father's time as a Sailor, although having said that I too have a Sailor in the mid-1700's but haven't found anything yet.
Lyn