For clarification: MassGIS publishes town corner coordinates from a professional survey.  I have also measured them, with less than professional equipment.  So far my judgement is that for my previous measurements, the state's coordinates are more reliable, but my current measurements might be similar.   Thus, I have aligned the boundary to the state's coordinates (transformed to ITRF2014).  Also, I put the historic boundary stone at my measurement -- which is only 1m away.  This is a compromise and shows the uncertainty, and that's what seems useful to me, the active local.  Feel free to message me if you are also local and think it should be different, or to bring it up on the MA email list.