I'm not familiar with this area - I'm hoping that you were!
I'm always puzzled by "what is officially a common and what isn't".  In some case it's obviously signed as such on the ground (and you might have get some bylaws posted - one near me has that).  Part of another one near me seems to be used as farmland currently - but maybe that was never part of, but only adjacent to, the "common" part?  I'm not sure how you'd tell...
