I found this in the 1911 (v57, p337) Proc. Som. Arch. Soc.
On Faulkland Green.. may be seen several standing stones, some of which were placed there many years ago by a local builder.
Well this may sound like a very vague (’some of which’ and ‘many years’), not that encouraging bit of information. But it does suggest the stones have been there a long time? and were brought from elsewhere? Ok so it’s not that helpful and could be complete swill. But I thought it might be worth sharing.