Now go and find some more ...

If there's one undiscovered ancient monument then there'll be another half dozen nearby. The proximity of the stone to a public footpath is very strong supporting evidence as it's likely that standing stones were also used as waymarkers and, we suppose, many trackways have followed a similar route for thousands of years. Squint down the sides of the stone - difficult in a hedge - and see if anything else is indicated. Use it as a starting point and work out, away from it. There'll be more.

And get it logged on the county sites and monument register - via County Hall environment unit. Getting it logged on this site is more difficult now - almost impossible, I'd say, like dropping a penny in a well and making a wish, but the other site is still accepting submissions. And the more you find the more opposition you will encounter - so, please, cultivate a thick skin and limitless patience - you'll need them both!