Thank you, November4,
The graves are on a hill at the rear of Parnham House in Beaminster, Dorset and the plot is enclosed by an iron fence (as can be seen).
I had to climb the fence and then search through many years of accumulated undergrowth to find the graves. Apparently, because it was a private plot, the owners of the house (an internationally renowned cabinet maker) were - I was told - not responsible or did not own the land. The care of the site had been entrusted to some local people but they were then either dead or unable to take care of the place.
Your photograph shows that the site has obviously been recovered to some reasonable standard but the bumpy ground shows that it had been neglected for sometime. I hope it is now being looked after as anyone's last resting place should be.
Old Duffer