The reason I think this may be James, son of John and Sarah is because of the burial location, in the same cemetery as his uncle Peter Wallover and aunt Margaret Walton Wallover. I believe we will find that most of John and Sarah's family affiliated with Protestant religions although they were baptized Catholic as children. (Sarah was originally Protestant and is listed as such in two of the baptism records: "Protestant", and "non-Catholic." Her daughter Prudence and son John both joined the Roxborough Baptist Church.
A James Willcox who was affiliated with the Quakers would have been buried in Quaker burial grounds, I think, but maybe that is too far of a stretch in my thinking. And it isn't a cousin James Willcox, whose family was still Catholic.
At any rate, I have not been able to find the death date for Sarah Walton Willcox. There IS a Sarah Wilcox buried next to this James, along with an Elizabeth. But I don't think is her, because it would make Sarah Walton Willcox over 100 years old when she died. :)
Name: James Willcox
Birth Date: abt 1806
Birth Place: Delaware Co, PA
Death Date: 27 Dec 1886
Death Place: Philadelphia, Philadelphia, Pennsylvania
Age at Death: 80
Burial Date: 30 Dec 1886
Burial Place: Philadelphia, Pennsylvania
Street address: 1228 N 12th St , 20th Ward
Residence: Philadelphia, Pennsylvania
Cemetery: Lower Merion
Marital Status: Married
FHL Film Number: 2025965
"Pennsylvania, Philadelphia City Death Certificates, 1803–1915." Index. FamilySearch, Salt Lake City, Utah, 2008, 2010. From originals housed at the Philadelphia City Archives. "Death Records."
SACRAMENTAL REGISTERS, p. 478
Wilcocks [Willcox], on the 19th*, by Rev. J. Rosseter, James, born Feb. 15, or John Wilcocks and his wife Mary Warton (perhaps Wharton;] sponsors—Peter Scravendyke and Anna Cassin.
1Error. John Willcox married Sarah Walton.—Jos. Willcox.
*19 Oct 1800