Linking the pics to the nearest site as part of a query is not uncommon here .
RA footprints are very rare in the UK particularly in the open air .
You do get rings without cups , sometimes with a boss instead of a cup ,but again pretty rare .
You also get rectangles or half a rectangle i.e. an L shape, but again rare .
There is always the possibility that they could be relatively recent and engraved using metal .