Arishmell, have you considered whether my William's parents were the Peter and Anna Stanbury who baptised their William on 25 Dec 1795 in Bickleigh, Plymouth?
I think I have found a burial for Peter in Bickleigh, Plymouth on 27 Oct 1816 for him which gives a birth year of 1760. Also a possible baptism for him onn 24 August 1766 at St Giles on the Heath (father: William, mother: Mary).
St Giles on the Heath is about 25 miles from Hatherleigh, and slightly longer to Bickleigh, Plymouth.