I like the look of this stone & would be interested to see a few more recent pikkies. However, it does look very similar to a number of naturally-worn stones on the heights of Rombalds Moor, off the paths east and west of Nixon's Station cairn. The markings on some of them are incredibly similar but, not being a geologist, wouldn't like to say the same processes have made the marks on this 'ere boulder Down South...