Slightly longer description of the cairn and cist from GGAT, hinting that there may be a deliberately incised V in one of the cist slabs:
The cairn described by OS workers (1975 & 1979) is a partially destroyed round barrow cist situated in open heathland. The mound is circular in form, the N area is almost level whilst the SE area is more substantial in height. It would appear that the N-NW-W of the mound has been robbed away leaving a slight curved earthwork around the cairn’s former boundary. To the central S area of the cairn is an impressive cist (diameter; 2m x 1.2m x height; 0.65m) of two long parallel flagstone slabs aligned NE-SW, with smaller slabs (0.4m) defining each open end. There is a linear incision mark (0.16m long) on the inside of the S cist slab that does not appear natural; the incision is ‘V’ shaped and may have been caused by prehistoric stone rubbing. To the S of the cist is the only area of exposed boulders.
Dimensions: diameter 15.5m; height 1.4m (max)