FYI, This is not likely to be the gravesite of John Walker (or his wife, Katherine Rutherford). White, 1902 Descendants of John Walker of Wigton Scotland states that they were buried in the cemetery of the Presbyterian Nottingham Church near Rising Sun. Rising Sun is actually in Cecil Maryland. The original Nottingham Presbyterian Church. That church, or at least its descendant church, has been at several different locations over the years, since its founding at Mouth of Octoraro on the Susquehannah, a few miles south of Rising Sun. Sometime in the 1730's that church was abandoned, with the congregation moving to their Rising Sun location. About 1740 the Congregation divided into "New Side/Old Side" congregations, with the Old side remaining in the original church, while the New Side built a new church a few miles away.
Eventually, the two congregations reunited and merged to form the West Nottingham Presbyterian Church. At that time both the New Side, and Old Side churches were abandoned. Interestingly enough, some of the gravestones from the cemetery original Nottingham Presbyterian were moved to the cemetery of the Nottingham Presbyterian. ---but only a few of them. Those stones can still be seen in the West Nottingham Cemetery. Alas, the stones for John Walker and wife Katherine Rutherford were not among those moved.

Eventually the Rising Sun church building was torn down. The cemetery remained for sometime, surrounded by a farmers field. Sometime in the 50's or 60's the field was converted to a residential area. Any surviving stones were lost at that time.

Today, the cemetery does not exist. Its original location is close to where the Rising Sun Middle School is now located, on the south side of West Pearl Street, between Cooper Ave. and Reynolds Ave.

https://www.google.com/maps/place/Nottingham+Cemetery,+Nottingham,+PA+19362/@39.7003721,-76.0678806,602m/data=!3m1!1e3!4m13!1m7!3m6!1s0x89c7b4fc04f786d9:0x365efc081b09cf41!2sNottingham+Cemetery,+Nottingham,+PA+19362!3b1!8m2!3d39.7521024!4d-76.0340232!3m4!1s0x89c7b4fc04f786d9:0x365efc081b09cf41!8m2!3d39.7521024!4d-76.0340232