Abandoned millstones at Oakwood Farm

A couple of abandoned millstones ready for market but never shipped. Two of many finished, half-finished, or just started grindstones scattered amongst the boulders of these slopes at the southern tip of the Pennines in the Peak District National Park. (A millstone is also the symbol of the national park.) The rock is a medium to coarse grained sandstone of the Carboniferous Period. The diameter of these stones is larger than most at around 1.8 m. They were usually cut from suitable rocks on site (the one they are leaning on might have been the next job) and used for grinding, crushing and sharpening depending on the grain size of the rock. The stones have different shapes for this range of uses. Many lie abandoned like these due to changes in technology impacting sales in the 18th and 18th century. I used a drone to photo them from all angles then processed using Agisoft. Any suggestions for improvements are welcome.