Whereas the site has always been within a fenced area, overgrown and neglected and with a landowner who didn’t want people to enter the site I am happy to report that it is now a delight to visit.
The grass has been cut back, and the fences have been repositioned. There is now no fence between the site and the layby/parking place. If you want to visit the immediately adjacent chambered tomb, though, be prepared to climb a (nice, new, shiny) fence and risk the wrath of the land owner.