Reply To: What did people do before Rashi invented Rashi tefillin?

I am not totally familiar with the various archeological finds but, to me, the central question about Rashi and Rabbeinu Tam’s tefillin is in the actual “mesorah”. After all, if my father and grandfather wore certain tefillin , which I wear today, and they inherited them from their parents and grandparents, how is it possible to have questionable tefillin?We have now close to a thousand years of two sets of tefillin and never has there been a third way and this is simply because we all wear tefillin of our parents and so forth. So, what happened to Rashi and his parents and grandparents? And, begging the question, how does Rabbeinu Tam reject his grandfather’s tefillin-that I never understood.