We researched Arbor Low for our webpages last year, the general opinion in the literature then was that the stones were simply the victims of shallow socket holes and that there had not been a concerted attempt at mass destruction.
Some of the stones have snapped and left embedded stumps, seven of these can be reliably identified and fortuitously these are well distributed around the circumference. The stumps suggest a continuous ring of circumferencially set stones.
Several stones have obviously been removed, probably for use as gateposts ( stone 35 is split and shows a drill hole ), at least four of the top sections belonging to the stumps mentioned above appear to be missing.
Personally, although we would love to see the original arrangement of the Low's stones, we think that their present state is preferable to a modern "reconstruction".