There are two other couples having children in Welcombe about the same time ,again address Hartland.
Joseph and Grace and John and Rebecca Hockridge.
Joseph Hockridge of Welcombe (b c 1781)and Grace Harwood married at Kilkhampton 25.8.1804
John ,husbandman and Rebecca Crocker at Bradworthy 8.4.1806 wit Thomas Hockeridge and John Wade.
The only early baptism before 1805 I can see at Welcombe is Thomas s of Thomas and Damaras in 23.4.1789
They married at Morwenstow Cornwall 20.10.1781 ,her name Damaris Burrow
He seems to be buried at Clovelly 14.6.1823 age 70.Damaris 30.1.1836 age 77
Joseph and Grace also at All Saints Clovelly 1778-4.8.1847 and 1782-27.1.1830
Thomas 1790-14.1.1879 of Eastacott.
Other children for Thomas and Damaras-Mary 25.7.1785 ,Damaras 16.4.1787 at Morwenstow.
This seems to suggest that Joseph is Mary's brother and they are both children of Thomas and Damaras
Just a thought
Ciderdrinker