Your comment about difficult parking upsets me. Park your car at the foot of the brae at Cragabus, and walk the 30 feet back to the stones. I should know. My granny was born in Cragabus, my father was brought up in Cragabus , as were all my ancestors. I lived in Cragabus every summer, when I as a boy.
The stones are known as Connachan's grave, allegedely a warrior who was killed in a battle in the field to the west of the stones. My granny told me that the main stone was cut and dragged frm the large hills overlooking Port Ellen lighthouse. If you look from Connaghan's grave, there is a distinct gap which could be where the stone orginated.
Cragabus is steeped in mystery. My granny told me a fairy piper could be heard playing around the back of Connaghan's.
I do recall that some excavation work took place in the early sixties but nothing as found. However, further up the road at middle Cragabus, a baby's body was found underneath a large stone.