Thanks Rudy,
I just spoke with Anne Grady on the phone. A nice woman. Unfortunitely, my samples are not well suited to a dendro analysis, party because they are softwood and more significantly because i do not have any sap wood to mark and end point on the trees growth.
She did lead me to Bill Flynt of Historic Deerfield who may be able to help in some way. I wll try him but I am getting the sense that my date based on a visual ring count and a few assumptions may be the best I am going to get....