Whilst both Richard Taylor and Sarah PURKIS were 'of this parish' when they married in Wimbish 13 Oct.1801, I cannot see any baptism in Wimbish between 1771 and 1785. His age is given as 84 on his burial 11 Aug.1859 indicating a birth c1775 on the 1851 census he is only 71 (c1779). I notice that Sarah and the two sons with them in 1851 all give Stoke as PoB whilst Richard does give Wimbish. I suspect that Stoke probably refers to the parish of Stoke by Clare just over the county border in Suffolk, but there are other possibles.
The only Taylor families with baptisms in Wimbish during that period are a Henry/Harry and Ann and a Mark and Ann, so is he perhaps a son of either of those couples but not baptised or was he baptised in another parish with different parents. I have had a quick look at surrounding parishes, Thaxted, Radwinter, Great Sampford, Debden and Saffron Walden with no success, so he may have come from further afield. Interestingly a Richard and Mary Taylor had two sons baptised in Wimbish in 1785 and 1787, as I cannot see a marriage for this couple in Wimbish around that time, did they perhaps move into the parish prior to those baptisms and already had some children. It would be expected that if they had several sons one would be a Richard.