The 16 pieces of the coped gravestone were found in a ditch next to the graveyard at Nisbet. Since then they have been put back together and the grave cover is now in the museum at Wilton Lodge in Hawick.

For a history of the respective churches of these fragments, see sites for Nisbet and Wheel.

It is uncertain whether the cross has been added to the Nisbet grave cover at a later date or is original to the monument. In form, it is similar to the now-missing cross from Nisbet. Coped grave covers which are straight along the top are often viewed as a late form of hogback and dates in the later 11thc or early 12thc have been suggested. Similar fishscale ornamented grave covers can be found nearby in the cemetery of the old church at Ancrum and inside the porch of the church at Bedrule (fragment).

A date about 1170 has been suggested for the Wheel voussoir. Earlier sawtooth is usually carved with the plane behind the sawtooth slanted backwards towards the top, giving a flatter effect. On the Castleton voussoir the back plane is slanted towards the bottom, which gives a more 3-D effect. This latter type seems to come into use during the 2nd half of the 12thc. The sill and top of a simple rounded of window of Romanesque form was also found in the 1914 excavations.