I can’t disagree with anything you’ve said, the route of the road did have a very ‘ancient trackway’ feel to it and I was struck by the almost constant view of the sea at the north end of the moor (down the Esk Valley and to Whitby?)
>If the stones were recent . . .. I would expect them to be dressed stones or at least of a uniform size and nature
Some of them did remind me of the fallen stones at the High Bridestones that I’d seen an hour or so before. Now, if I was the poor sap who had been ordered to put up some route markers 2-300 years ago, rather than carting some (valuable) stone a mile or so across the moor from the quarry I might be tempted to use some old stones that were already standing on the moor close by. Knock them into shape, stick a hole through for a lamp and stand them in place. Result - 1 set of way markers and 1 vanished stone circle/row. Total speculation of course but it might account for the differing shapes and sizes. . . .
-Chris