I finally made it to this stone, Ballybought (Baile Bocht) wart stone, after 5 aborted visits, livestock in the large field always putting me off. The stone is about 200 metres into the field from the little bridge that fords the north to south flowing stream, on the eastern side of the small valley.
The ovoid bullaun dominates the large, metre and a half long boulder, at least a foot wide on its longer axis. I didn't feel like testing its depth. There are very faint cupmarks on the boulder too. Lumps of quartzite speckle the granite. The stone seems to have been cut on its south-east edge, though many moons ago.
On leaving I realised there were livestock in the field still, hidden beyond the crest of the hill. Oh well.