Clwyd Powys Archaeological Trust list Maen Llog in its current position, as a ‘boulder’ of unknown date. It’s antiquity must be in doubt, as nobody else seems to list it. It really doesn’t look much like a standing stone (Barber’s hunch), but it does remind me of a photo I’ve seen of Carreg Pumpsaint which is thought to be a possible anvil stone (Roman or Medieval). This is just supposition of course.